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Longer titles found: Upper-convected time derivative (view)

searching for time derivative 277 found (342 total)

alternate case: Time derivative

Material derivative (1,919 words) [view diff] exact match in snippet view article find links to article

{\mathbf {x} }}=\mathbf {0} } is chosen, the time derivative becomes equal to the partial time derivative, which agrees with the definition of a partial
Total derivative (2,711 words) [view diff] exact match in snippet view article find links to article
i {\displaystyle x_{i}} which themselves depend on time. Then, the time derivative of L {\displaystyle L} is d L d t = d d t L ( t , x 1 ( t ) , … , x
Integral curve (816 words) [view diff] exact match in snippet view article find links to article
map α∗ : TJ → TM so that the following diagram commutes: Then the time derivative α′ is the composition α′ = α∗ o ι, and α′(t) is its value at some point t ∈ J
Kinematics (8,735 words) [view diff] exact match in snippet view article find links to article
average velocity approaches the instantaneous velocity, defined as the time derivative of the position vector, v = lim Δ t → 0 Δ r Δ t = d r d t = v x x ^
Vector fields in cylindrical and spherical coordinates (1,702 words) [view diff] exact match in snippet view article find links to article
second time derivative is of interest in physics, as it is found in equations of motion for classical mechanical systems. The second time derivative of a
Power (physics) (1,998 words) [view diff] exact match in snippet view article
is the rate with respect to time at which work is done; it is the time derivative of work: P = d W d t , {\displaystyle P={\frac {dW}{dt}},} where P
Absement (1,383 words) [view diff] no match in snippet view article find links to article
vs. time graph), so the displacement is the rate of change (first time-derivative) of the absement. The dimension of absement is length multiplied by
Incompressible flow (1,714 words) [view diff] exact match in snippet view article find links to article
\rho \,\mathrm {d} V}.} The conservation of mass requires that the time derivative of the mass inside a control volume be equal to the mass flux, J, across
PSR J0901–4046 (427 words) [view diff] exact match in snippet view article find links to article
the neutron star. PSR J0901–4046's period, combined with its period time derivative of 2.25×10−13 second/second, implies a characteristic age of 5.3 million
Lyapunov function (1,083 words) [view diff] exact match in snippet view article find links to article
strictly positive for y ≠ 0 {\displaystyle y\neq 0} , and for which the time derivative V ˙ = ∇ V ⋅ g {\displaystyle {\dot {V}}=\nabla {V}\cdot g} is non positive
Rotating reference frame (3,858 words) [view diff] exact match in snippet view article find links to article
frame of reference. Acceleration is the second time derivative of position, or the first time derivative of velocity a i   = d e f   ( d 2 r d t 2 ) i
Newmark-beta method (1,241 words) [view diff] exact match in snippet view article find links to article
the Newmark- β {\displaystyle \beta } method states that the first time derivative (velocity in the equation of motion) can be solved as, u ˙ n + 1 =
Quantum thermodynamics (4,487 words) [view diff] no match in snippet view article find links to article
Quantum thermodynamics is the study of the relations between two independent physical theories: thermodynamics and quantum mechanics. The two independent
London equations (2,013 words) [view diff] exact match in snippet view article find links to article
solutions were nonphysical, and thus postulated that not only was the time derivative of the above expression equal to zero, but also that the expression
List of physical quantities (187 words) [view diff] exact match in snippet view article find links to article
Acceleration a→ Rate of change of velocity per unit time: the second time derivative of position m/s2 L T−2 vector Action S Momentum of particle multiplied
Geomagnetic secular variation (778 words) [view diff] exact match in snippet view article find links to article
variation. In most models, the secular variation is the amortized time derivative of the magnetic field B {\displaystyle \mathbf {B} } , B ˙ {\displaystyle
Ergodic hypothesis (1,055 words) [view diff] exact match in snippet view article find links to article
viewed by an observer moving with the ensemble (i.e., the convective time derivative is zero). Thus, if the microstates are uniformly distributed in phase
Viscoelasticity (5,835 words) [view diff] exact match in snippet view article find links to article
is the stress, η is the viscosity of the material, and dε/dt is the time derivative of strain. The relationship between stress and strain can be simplified
Finite strain theory (10,030 words) [view diff] exact match in snippet view article find links to article
that involve the time-dependent deformation of a body often require a time derivative of the deformation gradient to be calculated. A geometrically consistent
Wiener equation (116 words) [view diff] exact match in snippet view article find links to article
{x} }{dt}}=g(t),} where v is velocity, x is position, d/dt is the time derivative, and g(t) may for instance be white noise. Since velocity changes instantly
Ehrenfest theorem (2,829 words) [view diff] exact match in snippet view article find links to article
named after Austrian theoretical physicist Paul Ehrenfest, relates the time derivative of the expectation values of the position and momentum operators x
Particle acceleration (423 words) [view diff] exact match in snippet view article find links to article
physics, acceleration (symbol: a) is defined as the rate of change (or time derivative) of velocity. It is thus a vector quantity with dimension length/time2
Calculus of moving surfaces (1,291 words) [view diff] case mismatch in snippet view article find links to article
calculus to deforming manifolds. Central to the CMS is the Tensorial Time Derivative ∇˙{\displaystyle {\dot {\nabla }}} whose original definition was put
Logarithmic Schrödinger equation (1,242 words) [view diff] exact match in snippet view article find links to article
relativistic version (with D'Alembertian instead of Laplacian and first-order time derivative) in 1969.. It is a classical wave equation with applications to extensions
Hamiltonian field theory (1,836 words) [view diff] exact match in snippet view article find links to article
}{\partial t}}\,,} in which the overdot denotes a partial time derivative ∂/∂t, not a total time derivative d/dt. For many fields φi(x, t) and their conjugates
Reynolds transport theorem (2,233 words) [view diff] exact match in snippet view article find links to article
reference configuration: it is constant in material coordinates. The time derivative of an integral over a volume is defined as d d t ( ∫ Ω ( t ) f ( x
Specific angular momentum (1,313 words) [view diff] exact match in snippet view article find links to article
{\displaystyle r} . r ¨ {\displaystyle {\ddot {\mathbf {r} }}} is the second time derivative of r {\displaystyle \mathbf {r} } . (the acceleration) G {\displaystyle
Cahn–Hilliard equation (1,043 words) [view diff] exact match in snippet view article find links to article
Here ∂ / ∂ t {\displaystyle \partial /{\partial t}} is the partial time derivative and ∇ 2 {\displaystyle \nabla ^{2}} is the Laplacian in n {\displaystyle
Maxwell stress tensor (2,684 words) [view diff] exact match in snippet view article find links to article
_{0}{\frac {\partial \mathbf {E} }{\partial t}}\times \mathbf {B} } The time derivative can be rewritten to something that can be interpreted physically, namely
Transport coefficient (349 words) [view diff] exact match in snippet view article find links to article
\rangle } is an ensemble average and the dot above the A denotes the time derivative. For times t {\displaystyle t} that are greater than the correlation
Green–Kubo relations (1,987 words) [view diff] exact match in snippet view article find links to article
of the integral of the equilibrium time correlation function of the time derivative of a corresponding microscopic variable A {\displaystyle A} (sometimes
Appell's equation of motion (1,565 words) [view diff] exact match in snippet view article find links to article
{q_{r}}}} is an arbitrary generalized acceleration, or the second time derivative of the generalized coordinates q r {\displaystyle q_{r}} , and Q r
Duffing equation (2,989 words) [view diff] no match in snippet view article find links to article
i.e. velocity, and x ¨ {\displaystyle {\ddot {x}}} is the second time-derivative of x , {\displaystyle x,} i.e. acceleration. The numbers δ , {\displaystyle
Energy operator (1,209 words) [view diff] exact match in snippet view article find links to article
function is Ψ=ei(kx−ωt){\displaystyle \Psi =e^{i(kx-\omega t)}} The time derivative of Ψ is ∂Ψ∂t=−iωei(kx−ωt)=−iωΨ.{\displaystyle {\frac {\partial \Psi
Diffusion Monte Carlo (1,140 words) [view diff] exact match in snippet view article find links to article
{\displaystyle E} . These functions are called stationary states, because the time derivative at any point x {\displaystyle x} is always the same, so the amplitude
Newton's laws of motion (15,363 words) [view diff] exact match in snippet view article find links to article
change over time. Newton's second law, in modern form, states that the time derivative of the momentum is the force: F → = d p → d t . {\displaystyle {\vec
Clausius–Duhem inequality (1,636 words) [view diff] exact match in snippet view article find links to article
}{T}}\right)+{\frac {\rho ~s}{T}}} where η ˙ {\displaystyle {\dot {\eta }}} is the time derivative of η {\displaystyle \eta } and ∇ ⋅ ( a ) {\displaystyle {\boldsymbol
Constant of motion (1,541 words) [view diff] exact match in snippet view article find links to article
quantity A {\displaystyle A} is a constant of the motion if its total time derivative is zero 0 = d A d t = ∂ A ∂ t + { A , H } , {\displaystyle 0={\frac
Virial theorem (7,565 words) [view diff] exact match in snippet view article find links to article
particle. Assuming that the masses are constant, G is one-half the time derivative of this moment of inertia 1 2 d I d t = 1 2 d d t ∑ k = 1 N m k r k
Josephson effect (4,398 words) [view diff] exact match in snippet view article find links to article
of the junction. To solve the above equation, first calculate the time derivative of the order parameter in superconductor A: ∂ ∂ t ( n A e i ϕ A ) =
Vector-valued function (2,975 words) [view diff] exact match in snippet view article find links to article
such as time t, then the equation above reduces to the first ordinary time derivative of a with respect to t, d a d t = ∑ i = 1 n d a i d t e i . {\displaystyle
D'Alembert's principle (2,389 words) [view diff] exact match in snippet view article find links to article
derivatives of the momenta of the system." By Newton's second law, the first time derivative of momentum is the force. The momentum of the i {\displaystyle i} -th
Theodore Modis (1,446 words) [view diff] exact match in snippet view article find links to article
relationship between Entropy and Complexity as the latter being the time derivative of the former. He currently lives in Lugano, Switzerland. He went to
Lions–Magenes lemma (495 words) [view diff] exact match in snippet view article find links to article
Banach space-valued functions, which provides a criterion for moving a time derivative of a function out of its action (as a functional) on the function itself
Equation of state (cosmology) (1,059 words) [view diff] exact match in snippet view article
constant, and a ¨ {\displaystyle {\ddot {a}}} is the second proper time derivative of the scale factor. If we define (what might be called "effective")
Continuum mechanics (7,426 words) [view diff] exact match in snippet view article find links to article
density (current), ρ ˙ {\displaystyle {\dot {\rho }}} is the material time derivative of ρ {\displaystyle \rho } , v ( x , t ) {\displaystyle \mathbf {v}
Duhamel's principle (1,941 words) [view diff] exact match in snippet view article find links to article
the distribution of heat energy u in Rn. Indicating by ut (x, t) the time derivative of u(x, t), the initial value problem is { u t ( x , t ) − Δ u ( x
Finite volume method for unsteady flow (2,115 words) [view diff] exact match in snippet view article find links to article
time dependent. It gets reflected in the governing equations as the time derivative of the properties are absent. For Studying Finite-volume method for
Sine wave (1,332 words) [view diff] exact match in snippet view article find links to article
passband. A nth-order high-pass filter approximately applies the nth time derivative of signals whose frequency band is significantly lower than the filter's
Deceleration parameter (1,070 words) [view diff] exact match in snippet view article find links to article
{\displaystyle q_{0}} from the other measured parameters as above). The time derivative of the Hubble parameter can be written in terms of the deceleration
Siacci's theorem (765 words) [view diff] exact match in snippet view article find links to article
the acceleration of a particle moving along a curve in space is the time derivative of its velocity. In most applications, the acceleration vector is expressed
Small control property (120 words) [view diff] exact match in snippet view article find links to article
exists a ‖ u ‖ < ε {\displaystyle \|u\|<\varepsilon } so that the time derivative of the system's Lyapunov function is negative definite at that point
Probability current (3,021 words) [view diff] exact match in snippet view article find links to article
particle, the integral in the first term of the preceding equation, sans time derivative, is the probability of obtaining a value within V when the position
Faraday paradox (5,655 words) [view diff] no match in snippet view article find links to article
law from Maxwell's equations and the Lorentz force law. Consider the time-derivative of flux through a possibly moving loop, with area Σ ( t ) {\displaystyle
Calculus (8,575 words) [view diff] exact match in snippet view article find links to article
mass times it's acceleration, which is the time derivative of velocity and thus the second time derivative of spatial position. Starting from knowing
Four-gradient (8,619 words) [view diff] exact match in snippet view article find links to article
example, the 4-acceleration A μ {\displaystyle A^{\mu }} is the proper-time derivative of the 4-velocity U μ {\displaystyle U^{\mu }} : d d τ U = ( U ⋅ ∂
Classical electromagnetism (1,841 words) [view diff] exact match in snippet view article find links to article
add a correction factor, which is generally done by subtracting the time derivative of the A vector potential described below. Whenever the charges are
Hasegawa–Mima equation (1,806 words) [view diff] exact match in snippet view article find links to article
timescale much slower than the scale of interest. This allows the time derivative in the momentum balance equation to be neglected. The ion temperature
Bosanquet equation (459 words) [view diff] exact match in snippet view article find links to article
Bosanquet equation is a differential equation that is second-order in the time derivative, similar to Newton's Second Law, and therefore takes into account the
Fictitious force (8,499 words) [view diff] exact match in snippet view article find links to article
relative to frame A, and so cannot include rotation of frame B. Taking a time derivative, the velocity of the particle is: d x A d t = d X A B d t + ∑ j = 1
Homopolar generator (2,387 words) [view diff] exact match in snippet view article find links to article
electromagnetic induction. This law, in its modern form, states that the full-time derivative of the magnetic flux through a closed circuit induces an electromotive
Hypoelastic material (1,129 words) [view diff] exact match in snippet view article find links to article
deformed) state in the step. Here the superior dot represents the material time derivative ( ∂ / ∂ t {\displaystyle \partial /\partial t} following a given material
Angular momentum (13,458 words) [view diff] exact match in snippet view article find links to article
{L} =I{\boldsymbol {\omega }}} which means that the torque (i.e. the time derivative of the angular momentum) is τ = d I d t ω + I d ω d t . {\displaystyle
Speed (1,627 words) [view diff] exact match in snippet view article find links to article
distance) travelled until time t {\displaystyle t} , the speed equals the time derivative of s {\displaystyle s} : v = d s d t . {\displaystyle v={\frac {ds}{dt}}
Torque (4,382 words) [view diff] no match in snippet view article find links to article
linear momentum and r is the position vector from the origin. The time-derivative of this is: d L d t = r × d p d t + d r d t × p . {\displaystyle {\frac
Langevin dynamics (625 words) [view diff] exact match in snippet view article find links to article
calculated from the particle interaction potentials; the dot is a time derivative such that X ˙ {\displaystyle {\dot {\mathbf {X} }}} is the velocity
Modal analysis using FEM (700 words) [view diff] exact match in snippet view article find links to article
[M]} is the mass matrix, [U¨]{\displaystyle [{\ddot {U}}]} is the 2nd time derivative of the displacement [U]{\displaystyle [U]} (i.e., the acceleration)
Control-Lyapunov function (1,661 words) [view diff] exact match in snippet view article find links to article
is positive for all r ≠ 0 {\displaystyle r\neq 0} . Now taking the time derivative of V {\displaystyle V} V ˙ = r r ˙ {\displaystyle {\dot {V}}=r{\dot
Volumetric flow rate (1,077 words) [view diff] exact match in snippet view article find links to article
fluid V through a surface per unit time t. Since this is only the time derivative of volume, a scalar quantity, the volumetric flow rate is also a scalar
Gauss–Legendre method (1,126 words) [view diff] exact match in snippet view article find links to article
function [td, j] = lorenz_dynamics(state) % return a time derivative and a Jacobian of that time derivative x = state(1); y = state(2); z = state(3); sigma
Galilean invariance (1,717 words) [view diff] exact match in snippet view article find links to article
{\displaystyle r'(t)=r(t)-vt.\,} The velocity of the particle is given by the time derivative of the position: u ′ ( t ) = d d t r ′ ( t ) = d d t r ( t ) − v =
Continuity equation (4,739 words) [view diff] exact match in snippet view article find links to article
fluid density, t is time, u is the flow velocity vector field. The time derivative can be understood as the accumulation (or loss) of mass in the system
Siméon Denis Poisson (4,390 words) [view diff] exact match in snippet view article find links to article
V}{\partial q_{i}}}=0,~~~~i=1,2,...,n.} Here, the dot notation for the time derivative is used, d q d t = q ˙ {\displaystyle {\frac {dq}{dt}}={\dot {q}}}
Matrix mechanics (10,035 words) [view diff] exact match in snippet view article find links to article
then H, considered as a matrix function of X and P, will have zero time derivative. dHdt=P∗dPdt+(X+3εX2)∗dXdt=0 ,{\displaystyle {dH \over dt}=P*{dP \over
Laplace equation for irrotational flow (428 words) [view diff] exact match in snippet view article find links to article
(\rho {\vec {v}})=0} The condition of incompressibility means that the time derivative of the density is 0, and that the density can be pulled out of the
Fluid kinematics (291 words) [view diff] exact match in snippet view article find links to article
types of terms: those involving the time derivative and those involving spatial derivatives. The time derivative portion is denoted as the local derivative
Bochner space (795 words) [view diff] exact match in snippet view article find links to article
{\displaystyle u\in L^{2}\left([0,T];H_{0}^{1}(\Omega )\right)} with time derivative ∂ u ∂ t ∈ L 2 ( [ 0 , T ] ; H − 1 ( Ω ) ) . {\displaystyle {\frac {\partial
Method of lines (692 words) [view diff] exact match in snippet view article find links to article
equation by using the method of false transients. In this method, a time derivative of the dependent variable is added to Laplace’s equation. Finite differences
Jefimenko's equations (1,646 words) [view diff] exact match in snippet view article find links to article
Coulomb's law for the static electric field. The second term is the time derivative of the first Coulombic term multiplied by r ′ c {\displaystyle {\frac
Phasor (4,877 words) [view diff] exact match in snippet view article find links to article
the diagram below from the previous Phase Difference tutorial. The time derivative or integral of a phasor produces another phasor. For example: Re ⁡
Euclidean vector (9,031 words) [view diff] exact match in snippet view article find links to article
Velocity is the time derivative of position. Its dimensions are length/time. Acceleration a of a point is vector which is the time derivative of velocity
Quadrupole (1,983 words) [view diff] exact match in snippet view article find links to article
means that it will have a non-zero first, and also a non-zero second time derivative (this is of course true regardless the choice of the coordinate system)
Linear motion (1,576 words) [view diff] exact match in snippet view article find links to article
{\displaystyle \Delta t} tend to zero, that is, the velocity is the time derivative of the displacement as a function of time. v = lim Δ t → 0 Δ x Δ t
Temporal difference learning (1,565 words) [view diff] case mismatch in snippet view article find links to article
See final chapter and appendix. Sutton, R. S.; Barto, A. G. (1990). "Time Derivative Models of Pavlovian Reinforcement" (PDF). Learning and Computational
Schrödinger equation (10,110 words) [view diff] exact match in snippet view article find links to article
t}}.} This has again the form of the Schrödinger equation, with the time derivative of the wave function being given by a Hamiltonian operator acting upon
Hamiltonian mechanics (9,275 words) [view diff] exact match in snippet view article find links to article
function of q alone (i.e., T and V are scleronomic). In this example, the time derivative of q is the velocity, and so the first Hamilton equation means that
Delta-v (2,148 words) [view diff] exact match in snippet view article find links to article
burn the mass of the spacecraft will decrease due to use of fuel, the time derivative of the mass being If now the direction of the force, i.e. the direction
European Pulsar Timing Array (539 words) [view diff] exact match in snippet view article find links to article
disturbances in space-time, caused by the motion of masses, if the third time derivative of the mass quadrupole moment is non-zero. These waves are very weak
String vibration (2,042 words) [view diff] exact match in snippet view article find links to article
x , t ) {\displaystyle y(x,t)} , and the coefficient of the second time derivative term is equal to 1 v 2 {\displaystyle {\frac {1}{v^{2}}}} ; thus v
Fourth, fifth, and sixth derivatives of position (1,793 words) [view diff] exact match in snippet view article find links to article
1088/0264-9381/21/11/006. ISSN 0264-9381. S2CID 250859930. Snap [the fourth time derivative] is also sometimes called jounce. The fifth and sixth time derivatives
Energy (7,454 words) [view diff] exact match in snippet view article find links to article
energy is defined in terms of the energy operator (Hamiltonian) as a time derivative of the wave function. The Schrödinger equation equates the energy operator
Cutoff frequency (1,847 words) [view diff] exact match in snippet view article find links to article
y,z,t)=\psi (x,y,z)e^{i\omega t}.} Substituting and evaluating the time derivative gives ( ∇ 2 + ω 2 c 2 ) ψ ( x , y , z ) = 0. {\displaystyle \left(\nabla
Action (physics) (3,074 words) [view diff] exact match in snippet view article
physical significance of this function is understood by taking its total time derivative d W d t = ∂ W ∂ q i q ˙ i = p i q ˙ i . {\displaystyle {\frac {dW}{dt}}={\frac
Invariant manifold (817 words) [view diff] exact match in snippet view article find links to article
a{\displaystyle a}. One can see this invariance by considering the time derivative ddt(y−x21+2a){\displaystyle {\tfrac {\mathrm {d} }{\mathrm {d} t}}\left(y-{\tfrac
Newtonian fluid (3,037 words) [view diff] exact match in snippet view article find links to article
order approximated by a strain tensor that changes with time. The time derivative of that tensor is the strain rate tensor, that expresses how the element's
Robot kinematics (792 words) [view diff] exact match in snippet view article find links to article
kinematics equations, which yields formulas for the joint parameters. The time derivative of the kinematics equations yields the Jacobian of the robot, which
Acoustic theory (2,262 words) [view diff] exact match in snippet view article find links to article
to 0. This similarly applies for the density perturbation times the time derivative of the velocity. Moreover, the spatial components of the material derivative
Hydrogeology (8,028 words) [view diff] exact match in snippet view article find links to article
simulation, by a corresponding steady-state simulation (where the time derivative in the groundwater flow equation is set equal to 0). There are two
Cylindrical coordinate system (2,136 words) [view diff] exact match in snippet view article find links to article
}}}+z\,{\boldsymbol {\hat {z}}}.} The velocity of the particle is the time derivative of its position, v = d r d t = ρ ˙ ρ ^ + ρ φ ˙ φ ^ + z ˙ z ^ , {\displaystyle
Related rates (1,674 words) [view diff] exact match in snippet view article find links to article
{\displaystyle \Phi _{B}} (and therefore the electromotive force) by taking the time derivative of the flux relation E = − d Φ B d t = B A sin ⁡ θ d θ d t {\displaystyle
RC circuit (2,913 words) [view diff] exact match in snippet view article find links to article
resistor must be equal in magnitude (but opposite in sign) to the time derivative of the accumulated charge on the capacitor. This results in the linear
Gravitational wave (12,635 words) [view diff] exact match in snippet view article find links to article
Birkhoff's theorem. More technically, the second time derivative of the quadrupole moment (or the l-th time derivative of the l-th multipole moment) of an isolated
Centrifugal force (5,725 words) [view diff] exact match in snippet view article find links to article
of the rotating frame (i.e. P = P1 i + P2 j +P3 k), then the first time derivative [dP/dt] of P with respect to the rotating frame is, by definition,
Derivative (7,184 words) [view diff] exact match in snippet view article find links to article
or the dot notation, a dot is placed over a symbol to represent a time derivative. If y {\displaystyle y} is a function of t {\displaystyle t} , then
Kepler orbit (5,982 words) [view diff] exact match in snippet view article find links to article
{\displaystyle \mathbf {a} } is the acceleration vector, the second time derivative of the position vector r {\displaystyle \mathbf {r} } Strictly speaking
Scale factor (cosmology) (1,938 words) [view diff] exact match in snippet view article
H(t)\equiv {{\dot {a}}(t) \over a(t)}} where the dot represents a time derivative. The Hubble parameter varies with time, not with space, with the Hubble
Fokker–Planck equation (6,474 words) [view diff] exact match in snippet view article find links to article
x')-\mathbb {P} _{t,t'}(x\mid x')\right)\,dx,\end{aligned}}} which is a time derivative. Finally we arrive to ∫ [ L p ( x ) ] P t , t ′ ( x ∣ x ′ ) d x = ∫
Streamlines, streaklines, and pathlines (1,739 words) [view diff] exact match in snippet view article find links to article
the velocity gradient along the streamline. For a steady flow, the time derivative of the velocity is zero: ∂ c ∂ t = 0 {\displaystyle {\frac {\partial
Lemaître–Tolman metric (1,741 words) [view diff] exact match in snippet view article find links to article
{\displaystyle R} , the function r ( τ , R ) {\displaystyle r(\tau ,R)} and its time derivative respectively provides its law of motion and radial velocity. An interesting
Electromagnetic radiation (9,550 words) [view diff] no match in snippet view article find links to article
in first-order spatial derivatives of the wave solution, while the time-derivative on the other side of the equations, which gives the other field, is
Electromagnetic radiation (9,550 words) [view diff] no match in snippet view article find links to article
in first-order spatial derivatives of the wave solution, while the time-derivative on the other side of the equations, which gives the other field, is
MACD (1,870 words) [view diff] exact match in snippet view article find links to article
approximately by the equivalent of a low-pass EMA filter of 38 days. The time derivative estimate (per day) is the MACD value divided by 14. The average series
Adiabatic invariant (3,423 words) [view diff] exact match in snippet view article find links to article
_{0}^{2\pi }p{\frac {\partial x}{\partial \theta }}\,d\theta .} The time derivative of this quantity is d J d t = ∫ 0 2 π ( d p d t ∂ x ∂ θ + p d d t ∂
Brownian dynamics (868 words) [view diff] exact match in snippet view article find links to article
where: X ˙ {\displaystyle {\dot {X}}} is the velocity, the dot being a time derivative U ( X ) {\displaystyle U(X)} is the particle interaction potential
Fermionic field (1,696 words) [view diff] exact match in snippet view article find links to article
It is surprising that the Hamiltonian density doesn't depend on the time derivative of ψ {\displaystyle \psi } , directly, but the expression is correct
Density matrix (5,163 words) [view diff] exact match in snippet view article find links to article
matrix is not time-dependent, and the relative sign ensures that the time derivative of the expected value ⟨ A ⟩ {\displaystyle \langle A\rangle } comes
Objective stress rate (4,359 words) [view diff] exact match in snippet view article find links to article
rate of the Cauchy stress is the Piola transformation of the material time derivative of the 2nd P-K stress. We thus define σ ∘ = J − 1   ϕ ∗ [ S ˙ ] {\displaystyle
Four-momentum (3,188 words) [view diff] exact match in snippet view article find links to article
is simply zero. The four-acceleration is proportional to the proper time derivative of the four-momentum divided by the particle's mass, so p μ A μ = η
Hamilton–Jacobi equation (8,107 words) [view diff] exact match in snippet view article find links to article
\ldots ,q_{N-1},q_{N})} A dot over a variable or list signifies the time derivative (see Newton's notation). For example, q ˙ = d q d t . {\displaystyle
Rock mass plasticity (3,598 words) [view diff] exact match in snippet view article find links to article
the mass density, ρ˙{\displaystyle {\dot {\rho }}} is the material time derivative of ρ{\displaystyle \rho }, v(x,t)=u˙(x,t){\displaystyle \mathbf {v}
Heat equation (9,818 words) [view diff] exact match in snippet view article find links to article
instead – like a partial differential equation involving a second-order time derivative. Some models of nonlinear heat conduction (which are also parabolic
Momentum (9,778 words) [view diff] exact match in snippet view article find links to article
given coordinate qi does not appear in the Lagrangian (although its time derivative might appear), then pj is constant. This is the generalization of the
Canonical transformation (10,413 words) [view diff] exact match in snippet view article find links to article
p_{N}\right).\end{aligned}}} A dot over a variable or list signifies the time derivative, e.g., q ˙ ≡ d q d t {\displaystyle {\dot {\mathbf {q} }}\equiv {\frac
Darcy's law (3,494 words) [view diff] exact match in snippet view article find links to article
both gas and porous medium properties). For very short time scales, a time derivative of flux may be added to Darcy's law, which results in valid solutions
Quantum superposition (6,020 words) [view diff] exact match in snippet view article find links to article
where R x → y {\displaystyle \scriptstyle R_{x\rightarrow y}} is the time derivative of the K matrix: R x → y = K x → y d t − δ x y d t . {\displaystyle
Superspace (2,266 words) [view diff] exact match in snippet view article find links to article
Q^{\dagger }\,\right\}=2i{\frac {\partial }{\partial t}}} where i times the time derivative is the Hamiltonian operator in quantum mechanics. Both Q and its adjoint
Van der Pol oscillator (2,484 words) [view diff] exact match in snippet view article find links to article
y=x−x3/3−x˙/μ{\displaystyle y=x-x^{3}/3-{\dot {x}}/\mu }, where the dot indicates the time derivative, the Van der Pol oscillator can be written in its two-dimensional form:
T-symmetry (4,234 words) [view diff] exact match in snippet view article find links to article
described with a linear differential equation that is first-order in the time derivative, which is generally the case in order for something to be validly called
Canonical commutation relation (2,998 words) [view diff] exact match in snippet view article find links to article
momentum P ^ {\displaystyle {\hat {P}}} are all linear operators. The time derivative of a quantum state is - i H ^ / ℏ {\displaystyle i{\hat {H}}/\hbar
Center-of-momentum frame (1,773 words) [view diff] exact match in snippet view article find links to article
velocity of the COM frame. Since V is the velocity of the COM, i.e. the time derivative of the COM location R (position of the center of mass of the system):
Heat (10,917 words) [view diff] exact match in snippet view article find links to article
time, is denoted by Q ˙ {\displaystyle {\dot {Q}}} , but it is not a time derivative of a function of state (which can also be written with the dot notation)
Earth's magnetic field (8,947 words) [view diff] exact match in snippet view article find links to article
electrical conductivity σ and the permeability μ . The term ∂B/∂t is the time derivative of the field; ∇2 is the Laplace operator and ∇× is the curl operator
Relativistic quantum mechanics (10,055 words) [view diff] exact match in snippet view article find links to article
asymmetric: infinite-order in space derivatives but only first order in the time derivative, which is inelegant and unwieldy. Again, there is the problem of the
Third derivative (530 words) [view diff] exact match in snippet view article find links to article
inflation is the derivative of inflation, opposite in sign to the second time derivative of the purchasing power of money. Stating that a function is decreasing
Newmark's sliding block (734 words) [view diff] exact match in snippet view article find links to article
displacements is obtained by integrating twice (acceleration is the second time derivative of displacement) the difference of the applied acceleration and the
Standing wave (6,571 words) [view diff] exact match in snippet view article find links to article
{m}{L_{y}}}\right)^{2}}}.} If the initial conditions for z(x,y,0) and its time derivative ż(x,y,0) are chosen so the t-dependence is a cosine function, then
T-duality (2,420 words) [view diff] exact match in snippet view article find links to article
also functions of time. Let x˙{\displaystyle {\dot {x}}} denote the time derivative of the constant mode x{\displaystyle x}. This represents a type of
Symplectic group (3,076 words) [view diff] exact match in snippet view article find links to article
P_{n})^{\mathrm {T} }} are new canonical coordinates, then, with a dot denoting time derivative, Z ˙ = M ( z , t ) z ˙ , {\displaystyle {\dot {\mathbf {Z} }}=M({\mathbf
Accelerating expansion of the universe (4,836 words) [view diff] exact match in snippet view article find links to article
epoch. The definition of "accelerating expansion" is that the second time derivative of the cosmic scale factor, a ¨ {\displaystyle {\ddot {a}}} , is positive
Minimal coupling (1,491 words) [view diff] exact match in snippet view article find links to article
terms as well, but the extra terms in the Lagrangian add up to a total time derivative of a scalar function, and therefore still produce the same Euler–Lagrange
Utility frequency (5,513 words) [view diff] exact match in snippet view article find links to article
region recovered. Rate of change of frequency (also RoCoF) is simply a time derivative of the utility frequency ( d f / d t {\displaystyle {df}/{dt}} ), usually
Granular material (4,215 words) [view diff] exact match in snippet view article find links to article
+2\left\langle \varepsilon (t)\right\rangle ^{2}\right)\end{aligned}}} Now the time derivative of the second moment: d ⟨ ε 2 ⟩ d t = l i m d t → 0 ⟨ ε 2 ( t + d t
Electro–optic effect (879 words) [view diff] no match in snippet view article find links to article
electric fields, as is the case with conventional probes sensitive to the time-derivative of the electric field. Electro-optic measurements of strong electromagnetic
Euler–Lagrange equation (4,831 words) [view diff] exact match in snippet view article find links to article
Here, q ˙ ( t ) {\displaystyle {\dot {\boldsymbol {q}}}(t)} is the time derivative of q ( t ) . {\displaystyle {\boldsymbol {q}}(t).} When we say stationary
Hamilton's principle (2,268 words) [view diff] exact match in snippet view article find links to article
dependent on time and the product rule is needed to compute the total time derivative d d t m r 2 φ ˙ {\textstyle {\frac {d}{dt}}mr^{2}{\dot {\varphi }}}
Ostwald ripening (2,201 words) [view diff] exact match in snippet view article find links to article
an approach that respects the meanings of all terms is to take the time derivative of the equation to eliminate ⟨R⟩0 and t. Another such approach is to
Macroscopic quantum phenomena (3,324 words) [view diff] exact match in snippet view article find links to article
{\vec {B}}\right)} and using the general expression for the co-moving time derivative d v → s d t = ∂ v → s ∂ t + 1 2 ∇ → v s 2 − v → s × ( ∇ → × v → s )
Uflyand-Mindlin plate theory (4,344 words) [view diff] exact match in snippet view article find links to article
Wojnar. In 1994, Elishakoff suggested to neglect the fourth-order time derivative in Uflyand-Mindlin equations. A similar, but not identical, theory
Lorentz force (8,238 words) [view diff] exact match in snippet view article find links to article
position vector of the charged particle, t is time, and the overdot is a time derivative. A positively charged particle will be accelerated in the same linear
Duhamel's integral (1,732 words) [view diff] exact match in snippet view article find links to article
e^{-Bt}+C_{2}\cdot e^{-At}+{\frac {Q_{t}\cdot e^{-At}-R_{t}\cdot e^{-Bt}}{P}}} with time derivative: dxdt=−Ae−At⋅C2−Be−Bt⋅C1+1P[Qt˙⋅e−At−AQt⋅e−At−Rt˙⋅e−Bt+BRt⋅e−Bt]{\displaystyle
Scanning tunneling microscope (7,075 words) [view diff] exact match in snippet view article find links to article
}(t)|^{2}} divided by d t , {\displaystyle \mathrm {d} t,} which is the time derivative of | c ν ( t ) | 2 , {\displaystyle |c_{\nu }(t)|^{2},} Γ μ → ν   =
Landau–Lifshitz–Gilbert equation (1,341 words) [view diff] exact match in snippet view article find links to article
term in the Landau–Lifshitz (LL) equation by one that depends on the time derivative of the magnetization: This is the Landau–Lifshitz–Gilbert (LLG) equation
Discretization of Navier–Stokes equations (1,176 words) [view diff] exact match in snippet view article find links to article
difference for the time derivative and central difference for the spatial derivatives. For both momentum equations, the time derivative becomes ∂ u i ∂ t
Toda lattice (1,062 words) [view diff] exact match in snippet view article find links to article
= LP - PL is the Lie commutator of the two operators) is equivalent to the time derivative of Flaschka's variables. The choice L ( t ) f ( n ) = a ( n , t ) f
Quantum field theory (14,868 words) [view diff] no match in snippet view article find links to article
the Lagrangian density, ϕ ˙ {\displaystyle {\dot {\phi }}} is the time-derivative of the field, ∇ is the gradient operator, and m is a real parameter
Second law of thermodynamics (15,498 words) [view diff] exact match in snippet view article find links to article
of matter entering the system. It should not be confused with the time derivative of the entropy. If matter is supplied at several places we have to
Solow–Swan model (4,941 words) [view diff] no match in snippet view article find links to article
{\displaystyle {\frac {dK(t)}{dt}}} , the derivative with respect to time. Derivative with respect to time means that it is the change in capital stock—output
Laplace–Runge–Lenz vector (10,209 words) [view diff] exact match in snippet view article find links to article
{\displaystyle \mathbf {L} } . Specifying to inverse-square central forces, the time derivative of p × L {\displaystyle \mathbf {p} \times \mathbf {L} } is d d t p
RLC circuit (6,606 words) [view diff] exact match in snippet view article find links to article
For the case where the source is an unchanging voltage, taking the time derivative and dividing by L leads to the following second order differential
Special relativity (21,425 words) [view diff] exact match in snippet view article find links to article
where m is the invariant mass. The four-acceleration is the proper time derivative of 4-velocity: A μ = d U μ d τ . {\displaystyle A^{\mu }={\frac {dU^{\mu
Wannier function (2,047 words) [view diff] exact match in snippet view article find links to article
change in polarization during a continuous physical process is the time derivative of the polarization and also can be formulated in terms of the Berry
Reynolds-averaged Navier–Stokes equations (2,374 words) [view diff] exact match in snippet view article find links to article
integration in time removes the time dependence of the resultant terms, the time derivative must be eliminated, leaving: ρ u ¯ j ∂ u ¯ i ∂ x j = ρ f i ¯ + ∂ ∂
Heaviside–Lorentz units (2,242 words) [view diff] exact match in snippet view article find links to article
easy to recall where factors of c go in the Maxwell equation. Every time derivative comes with a 1 / c, which makes it dimensionally the same as a space
Klein–Gordon equation (6,535 words) [view diff] exact match in snippet view article find links to article
(mc^{2})^{2}\phi .} Applying this yields the non-relativistic limit of the second time derivative of ψ {\displaystyle \psi } , ∂ ψ ∂ t = ( − i m c 2 ℏ ϕ + ∂ ϕ ∂ t )
Equation-free modeling (3,263 words) [view diff] exact match in snippet view article find links to article
right plot shows the time derivative of the restricted solution as a function of time (blue curve), as well as the time derivative dU/dt{\displaystyle
Analytic signal (2,673 words) [view diff] exact match in snippet view article find links to article
corresponding s m ( t ) {\displaystyle s_{\mathrm {m} }(t)} . The time derivative of the unwrapped instantaneous phase has units of radians/second, and
Larmor formula (2,434 words) [view diff] exact match in snippet view article find links to article
The above inner product can also be written in terms of β and its time derivative. Then the relativistic generalization of the Larmor formula is (in
Feedback linearization (2,241 words) [view diff] exact match in snippet view article find links to article
structure of this target system, we use the Lie derivative. Consider the time derivative of (2), which can be computed using the chain rule, y ˙ = d h ( x )
Bremsstrahlung (9,295 words) [view diff] exact match in snippet view article find links to article
permittivity, β ˙ {\displaystyle {\dot {\boldsymbol {\beta }}}} signifies a time derivative of β {\displaystyle {\boldsymbol {\beta }}} , and q is the charge of
Axion (7,431 words) [view diff] exact match in snippet view article find links to article
set to unity. In this unit system, they are: Above, a dot denotes a time derivative and the axion–photon coupling is g a γ γ {\displaystyle g_{a\gamma
Itô calculus (4,461 words) [view diff] exact match in snippet view article find links to article
representation theorem can be interpreted formally as saying that α is the "time derivative" of M with respect to Brownian motion B, since α is precisely the process
Wheeler–Feynman absorber theory (3,738 words) [view diff] exact match in snippet view article find links to article
A ) i j {\displaystyle (V_{R})_{j}^{i}-(V_{A})_{i}^{j}} is a total time derivative, i.e. a divergence in the calculus of variations, and thus it gives
AC motor (6,360 words) [view diff] exact match in snippet view article find links to article
centered on the field. These induced currents are proportional to the time derivative of the magnetic field, leading it by 90 degrees. This puts the eddy
Baryon acoustic oscillations (3,220 words) [view diff] no match in snippet view article find links to article
{\frac {\dot {a}}{a}}\!} where a ˙ {\displaystyle {\dot {a}}} is the time-derivative of the scale factor. The Friedmann equations express the expansion
Quasispecies model (2,952 words) [view diff] exact match in snippet view article find links to article
the state change over one moment of time, then we can state that the time derivative of n i {\displaystyle n_{i}} is given by this difference, n ˙ i = n
Segregated Runge–Kutta methods (786 words) [view diff] exact match in snippet view article find links to article
while z{\displaystyle z} is known as the algebraic variable. The time derivative of the differential variable, y˙{\displaystyle {\dot {y}}}, depends
Pendulum (mechanics) (7,293 words) [view diff] exact match in snippet view article
|\mathbf {L} |=mr^{2}\omega =m\ell ^{2}{\frac {d\theta }{dt}}.} and its time derivative d d t | L | = m ℓ 2 d 2 θ d t 2 , {\displaystyle {\frac {d}{dt}}|\mathbf
Goldstone boson (3,697 words) [view diff] exact match in snippet view article find links to article
{x^{2}}{2A^{2}}}}\right)\cdot J,} a state with approximately vanishing time derivative is produced, ‖ d d t Q A | 0 ⟩ ‖ ≈ 1 A ‖ Q A | 0 ⟩ ‖ . {\displaystyle
Wave equation (10,120 words) [view diff] exact match in snippet view article find links to article
where the double dot on u ¨ {\displaystyle {\ddot {u}}} denotes double time derivative of u, ∇ is the nabla operator, and ∇2 = ∇ · ∇ is the (spatial) Laplacian
Differentiator (1,579 words) [view diff] exact match in snippet view article find links to article
{dV_{\text{in}}}{dt}}.} Consequently, The output voltage is proportional to the time derivative of the input voltage with a gain of R C . {\displaystyle RC.} Hence
Bohr–Van Leeuwen theorem (1,564 words) [view diff] exact match in snippet view article find links to article
{a} _{i}\cdot {\dot {\mathbf {r} }}_{i},} where the dot represents a time derivative and a i {\displaystyle \mathbf {a} _{i}} are vector coefficients depending
Melnikov distance (3,735 words) [view diff] no match in snippet view article find links to article
}^{s}} respectively. Taking the time-derivative of this function allows for some simplifications. The time-derivative of one of the terms in eq. (7) is
Self-tuning (1,282 words) [view diff] exact match in snippet view article find links to article
systems, some characteristic of control quality is used (e.g., the first time derivative of a controlled parameter). Automatic tuning makes sure that this characteristic
Thomas precession (4,713 words) [view diff] exact match in snippet view article find links to article
γ=1/√(1-v^2/c^2), the Lorentz factor. This is easily shown by taking the second time derivative of that dot product. Because this angular frequency exceeds ω, the
Fractional calculus (7,149 words) [view diff] exact match in snippet view article find links to article
characterized by using fractional-order diffusion equation models. The time derivative term corresponds to long-time heavy tail decay and the spatial derivative
Motion simulator (7,203 words) [view diff] exact match in snippet view article find links to article
threshold is not a linear acceleration but rather a jerk motion (third time derivative of position), and the reported threshold value is on the order of 0
Diffusion MRI (9,171 words) [view diff] exact match in snippet view article find links to article
Then, given conservation of mass, the continuity equation relates the time derivative of the concentration with the divergence of the flux: ∂ ρ ( x , t )
Inverse scattering transform (2,265 words) [view diff] exact match in snippet view article find links to article
or its derivatives. The self-adjoint operator L{\textstyle L} has a time derivative Lt{\textstyle L_{t}} and generates a eigenvalue (spectral) equation
Aircraft flight dynamics (8,497 words) [view diff] exact match in snippet view article find links to article
equal to the centripetal acceleration. The moment equation is the time derivative of the angular momentum: M = B d 2 θ d t 2 {\displaystyle M=B{\frac
Tunnel magnetoresistance (3,271 words) [view diff] exact match in snippet view article find links to article
operator T ^ {\displaystyle {\hat {\mathbf {T} }}} is obtained from the time derivative of the spin operator: T ^ = d S ^ d t = − i ℏ [ ℏ 2 σ , H ^ ] {\displaystyle
Modelica (2,620 words) [view diff] exact match in snippet view article find links to article
time-invariant and the 'der' operator, which represents (symbolically) the time derivative of a variable. Also worth noting are the documentation strings that
Added mass (1,818 words) [view diff] exact match in snippet view article find links to article
quasi-momentum: the added mass times the body acceleration is equal to the time derivative of the fluid quasi-momentum. Unsteady forces due to a change of the
Lambda-CDM model (11,069 words) [view diff] no match in snippet view article find links to article
{\frac {\dot {a}}{a}},} where a ˙ {\displaystyle {\dot {a}}} is the time-derivative of the scale factor. The first Friedmann equation gives the expansion
Transition path sampling (1,517 words) [view diff] no match in snippet view article find links to article
is either 1 if the system at time t is in state X or 0 if not. The time-derivative C'(t) starts at time 0 at the transition state theory (TST) value kABTST
Almost periodic function (2,838 words) [view diff] no match in snippet view article find links to article
f_{n}(t)\ } are very nearly harmonic but not necessarily exactly so. The time-derivative of φ n ( t )   {\displaystyle \varphi _{n}(t)\ } , that is φ n ′ (
Pilot wave theory (3,352 words) [view diff] exact match in snippet view article find links to article
{d}{dt}}\,{\vec {v}}=-{\vec {\nabla }}(V+Q)~,} where the hydrodynamic time derivative is defined as d d t = ∂ ∂ t + v → ⋅ ∇ →   . {\displaystyle {\frac {d}{dt}}={\frac
Acoustic wave equation (1,631 words) [view diff] exact match in snippet view article find links to article
{\partial u}{\partial t}}+{\frac {\partial p}{\partial x}}=0} . Taking the time derivative of the continuity equation and the spatial derivative of the force
Stephen Timoshenko (2,620 words) [view diff] exact match in snippet view article find links to article
Timoshenko and P. Ehrenfest overestimate the importance of the fourth-order time derivative in their theory of beams?", Journal of Vibration and Acoustics, Vol
Lindbladian (3,718 words) [view diff] exact match in snippet view article find links to article
solve. A final assumption is the Born-Markov approximation that the time derivative of the density matrix depends only on its current state, and not on
Leibniz integral rule (11,107 words) [view diff] exact match in snippet view article find links to article
space variables only and ω ˙ {\displaystyle {\dot {\omega }}} is the time derivative of ω. If we move into spacetime M = R × R 3 {\displaystyle M=\mathbb
Thermal inductance (1,137 words) [view diff] exact match in snippet view article find links to article
and an electric inductance switched in series. It was shown that the time derivative of the heat current is proportional to the negative temperature difference
Hierarchical equations of motion (1,305 words) [view diff] exact match in snippet view article find links to article
\eta \gamma ^{2}\omega /\pi (\gamma ^{2}+\omega ^{2})} and taking the time derivative of the path integral form density matrix the equation and writing it
Electro-optic modulator (1,789 words) [view diff] no match in snippet view article find links to article
voltage traces, as is the case for conductive probes sensitive to the time-derivative of the electric field. EOMs can be based on many operating principles
Spherically symmetric spacetime (1,784 words) [view diff] exact match in snippet view article find links to article
_{r}=4\pi rf} where ∇ t {\displaystyle \nabla _{t}} is the covariant time derivative (and ∇ {\displaystyle \nabla } the Levi-Civita connection), p {\displaystyle
Mathematical descriptions of the electromagnetic field (6,736 words) [view diff] exact match in snippet view article find links to article
principle of extremal action, see electromagnetic tensor. Often, the time derivative in the Faraday–Maxwell equation motivates calling this equation "dynamical"
Memristor (13,866 words) [view diff] exact match in snippet view article find links to article
charge (x = q) and since the charge is related to the current via the time derivative dq/dt = i(t). Thus for pure memristors f (i.e. the rate of change of
Dissipative operator (1,534 words) [view diff] exact match in snippet view article find links to article
either diminishes or leaves unchanged the norm of its operand). If the time derivative of a point x in the space is given by Ax, then the time evolution is
Optical tweezers (9,479 words) [view diff] exact match in snippet view article find links to article
\right)\right].\\\end{aligned}}} The second term in the last equality is the time derivative of a quantity that is related through a multiplicative constant to
Navier–Stokes existence and smoothness (5,196 words) [view diff] exact match in snippet view article find links to article
that the velocity and pressure do not vary with time), we can set the time derivative terms equal to zero: ( v ⋅ ∇ ) v = − 1 ρ ∇ p + ν Δ v {\displaystyle
Strain-rate tensor (2,246 words) [view diff] no match in snippet view article find links to article
the layers. Stress tensor (disambiguation) Finite strain theory § Time-derivative of the deformation gradient, the spatial and material velocity gradient
Temporal discretization (883 words) [view diff] exact match in snippet view article find links to article
t}+(1-f)\cdot F_{\varphi }^{t}]\,\Delta t} After discretizing the time derivative, function F ( φ ) {\displaystyle F(\varphi )} remains to be evaluated
Fermi's golden rule (3,906 words) [view diff] exact match in snippet view article find links to article
Defining Δ = ω f i − ω {\displaystyle \Delta =\omega _{fi}-\omega } the time derivative of sin 2 ⁡ ( Δ t / 2 ) / Δ 2 {\displaystyle \sin ^{2}(\Delta t/2)/\Delta
Finite-difference time-domain method (5,629 words) [view diff] exact match in snippet view article find links to article
examined, it can be seen that the change in the E-field in time (the time derivative) is dependent on the change in the H-field across space (the curl)
Formulations of special relativity (2,611 words) [view diff] exact match in snippet view article find links to article
objects moving through four-dimensional space appears from the regular time derivative c 2 = ( d x / d t ) 2 + ( d y / d t ) 2 + ( d z / d t ) 2 + ( c d τ
Potential vorticity (3,613 words) [view diff] exact match in snippet view article find links to article
{\frac {DA_{e}}{Dt}},} (1) where DDt{\textstyle {\frac {D}{Dt}}} is the time derivative in the rotational frame (not inertial frame), C{\displaystyle C} is
Parallactic angle (1,514 words) [view diff] exact match in snippet view article find links to article
as h˙=2πTs{\displaystyle {\dot {h}}={\frac {2\pi }{T_{s}}}} and the time derivative of the tan q expression is q˙1cos2⁡q=cos⁡φ[cos⁡hcos⁡δsin⁡φ−sin⁡δco
Ritz method (2,435 words) [view diff] exact match in snippet view article find links to article
potential energy term. The kinetic energy term involves the square of the time derivative of y ( x , t ) {\displaystyle y(x,t)} and thus gains a factor of ω
LSZ reduction formula (5,694 words) [view diff] exact match in snippet view article find links to article
inner product. Rewriting the limits in terms of the integral of a time derivative, we have M=−1Z∫d4x1∂0(eip1⋅x1⟨β out|Ψ¯(x1)γ0up1s1|α′ in⟩){\displaystyle
Rigid rotor (5,474 words) [view diff] exact match in snippet view article find links to article
be shown that ω{\displaystyle {\boldsymbol {\omega }}} is not the time derivative of any vector, in contrast to the usual definition of velocity. The
Zwanzig projection operator (2,009 words) [view diff] exact match in snippet view article find links to article
generic Langevin equation is obtained by applying this equation to the time derivative of a slow variable A{\displaystyle A}, dA(Γ,t)/dt=eitL(dA(Γ,t)/dt)t=0{\displaystyle
Curie–von Schweidler law (927 words) [view diff] no match in snippet view article find links to article
relation is given by the convolution of the capacitance with the first time-derivative of the voltage, i.e., Q(t)=C(t)∗V˙(t){\displaystyle Q(t)=C(t)*{\dot
Sound from ultrasound (3,862 words) [view diff] exact match in snippet view article find links to article
then integrating twice to invert the effect of the double partial-time derivative. The analogue electronic circuit equivalents of a square root function
Metropolis-adjusted Langevin algorithm (1,306 words) [view diff] exact match in snippet view article find links to article
{\dot {X}}=\nabla \log \pi (X)+{\sqrt {2}}{\dot {W}}} driven by the time derivative of a standard Brownian motion W {\displaystyle W} . (Note that another
Biological neuron model (14,904 words) [view diff] exact match in snippet view article find links to article
}{\frac {dV(t)}{dt}}=-\sum _{i}I_{i}(t,V).} The above equation is the time derivative of the law of capacitance, Q = CV where the change of the total charge
Tides in marginal seas (3,692 words) [view diff] exact match in snippet view article find links to article
possible to get an expression for η {\displaystyle \eta } , by taking the time derivative of the continuity equation and substituting the momentum equation:
Governing equation (897 words) [view diff] no match in snippet view article find links to article
mechanics are all balance equations, and as such each of them contains a time-derivative term which calculates how much the dependent variable change with time
Rashba effect (2,749 words) [view diff] exact match in snippet view article find links to article
electron experiences must be zero given the connection between the time derivative of spatially averaged momentum, which vanishes as a bound state, and
Spacecraft magnetometer (3,078 words) [view diff] exact match in snippet view article find links to article
per second. Following Lenz's law, the voltage is proportional to the time derivative of magnetic flux. The voltage will be amplified by the apparent permeability
Hamiltonian (control theory) (3,812 words) [view diff] exact match in snippet view article
Lagrangian is evaluated with q˙{\displaystyle {\dot {q}}} representing the time derivative of the state's evolution and p{\displaystyle p}, the so-called "conjugate
History of Maxwell's equations (3,823 words) [view diff] exact match in snippet view article find links to article
F=p˙{\displaystyle F={\dot {p}}}, where p˙{\displaystyle {\dot {p}}} is the time derivative of the momentum p{\displaystyle p}. This seems a trivial enough fact
Superfluid helium-4 (4,819 words) [view diff] exact match in snippet view article find links to article
{\displaystyle {\vec {v}}_{s}} is the velocity of the superfluid component. The time derivative is the so-called hydrodynamic derivative, i.e. the rate of increase
Euler equations (fluid dynamics) (13,166 words) [view diff] exact match in snippet view article
{\partial \mathbf {u} }{\partial t}}} In case of a steady flow the time derivative of the flow velocity disappears, so the momentum equation becomes:
Adiabatic theorem (4,594 words) [view diff] exact match in snippet view article find links to article
time-dependent adiabatic Hamiltonian, and the overdot represents a time derivative. Comparison of the initial conditions used with the values of the state
Flow plasticity theory (2,005 words) [view diff] exact match in snippet view article find links to article
{F}}^{e})^{-1}\,.\end{aligned}}} where a superposed dot indicates a time derivative. We can write the above as l = l e + F e ⋅ L p ⋅ ( F e ) − 1 . {\displaystyle
Electrical cardiometry (973 words) [view diff] exact match in snippet view article find links to article
shape similar to an arterial pressure waveform. The calculated first time derivative of dZ(t) is the d Z ( t ) d t {\displaystyle {\frac {dZ(t)}{dt}}} waveform
Speckle tracking echocardiography (1,991 words) [view diff] exact match in snippet view article find links to article
between two kernels into strain (deformation). Strain rate will then be time derivative of strain. In some commercial applications, the acoustic markers are
Cauchy momentum equation (5,379 words) [view diff] exact match in snippet view article find links to article
{\partial \mathbf {u} }{\partial t}}} In case of a steady flow the time derivative of the flow velocity disappears, so the momentum equation becomes:
Schrödinger field (3,795 words) [view diff] exact match in snippet view article find links to article
seems naively to be overcounting. This is not the case, because the time derivative term in L includes the overlap between the different field states.
Magnus expansion (3,490 words) [view diff] exact match in snippet view article find links to article
A(t), using a Poincaré−Hausdorff matrix identity, he could relate the time derivative of Ω to the generating function of Bernoulli numbers and the adjoint
Zilch (electromagnetism) (1,240 words) [view diff] exact match in snippet view article
chirality was offered in 2012; optical chirality is to the curl or time derivative of the electromagnetic field what helicity, spin and related quantities
Denavit–Hartenberg parameters (4,090 words) [view diff] exact match in snippet view article find links to article
{\displaystyle i} . The acceleration matrix can be defined as the sum of the time derivative of the velocity plus the velocity squared H i , j ( k ) = W ˙ i , j
Angular velocity tensor (2,309 words) [view diff] exact match in snippet view article find links to article
In general, the angular velocity in an n-dimensional space is the time derivative of the angular displacement tensor, which is a second rank skew-symmetric
Theoretical and experimental justification for the Schrödinger equation (6,109 words) [view diff] exact match in snippet view article find links to article
^{2}=-{\frac {\hbar }{2m}}} and H j j = 0. {\displaystyle H_{jj}=0.} The time derivative term in the transition equation can be identified with the energy of
Kapitza's pendulum (2,714 words) [view diff] exact match in snippet view article find links to article
}}^{2}+ml(g+a~\nu ^{2}\cos \nu t)\cos \varphi ,} up to irrelevant total time derivative terms. The differential equation φ ¨ = − ( g + a   ν 2 cos ⁡ ν t )
Rayleigh–Kuo criterion (3,267 words) [view diff] exact match in snippet view article find links to article
{\displaystyle u} in the zonal direction, the time derivative of the mean flow U {\displaystyle U} and the time derivative of β y {\displaystyle \beta y} are zero
Thin-film equation (1,378 words) [view diff] exact match in snippet view article find links to article
fingering instability in gravity driven flow. The lack of a second-order time derivative in the thin-film equation is a result of the assumption of small Reynold's
Hamiltonian constraint (3,310 words) [view diff] exact match in snippet view article find links to article
the integrated densitized trace of the extrinsic curvature is the "time derivative of the volume". Misner, Charles W.; Thorne, Kip S.; Wheeler, John Archibald
Oseen equations (5,343 words) [view diff] exact match in snippet view article find links to article
While spatial derivatives are equal in both coordinate systems, the time derivative that appears in the equations satisfies: ∂ u → ( x → , t ) ∂ t = ∑
Hicks equation (2,149 words) [view diff] exact match in snippet view article find links to article
either the radial or axial momentum equations (after removing the time derivative term) to solve for ω θ {\displaystyle \omega _{\theta }} . For instance
Stability derivatives (3,157 words) [view diff] exact match in snippet view article find links to article
equation of motion governing the rotation of the body is derived from the time derivative of angular momentum: N=Cd2ψdt2{\displaystyle N=C{\frac {d^{2}\psi }{dt^{2}}}}
Stokes approximation and artificial time (432 words) [view diff] exact match in snippet view article find links to article
consisting of Navier stokes equation and continuity equations with time derivative of pressure, then the solution will be same as the stationary solution
Schamel equation (2,174 words) [view diff] exact match in snippet view article find links to article
S-equation. A further generalization is obtained by replacing the first time derivative by a Riesz fractional derivative yielding a time-fractional S-equation
Newton-X (2,241 words) [view diff] no match in snippet view article find links to article
(February 2009). "Optimization of mixed quantum-classical dynamics: Time-derivative coupling terms and selected couplings". Chemical Physics. 356 (1–3):
Dynamical pictures (3,911 words) [view diff] exact match in snippet view article find links to article
Differentiation was according to the product rule, while ∂A/∂t is the time derivative of the initial A, not the A(t) operator defined. The last equation
Quartz crystal microbalance (8,791 words) [view diff] exact match in snippet view article find links to article
speed is termed "mechanical impedance". Note: Here, speed means the time derivative of a displacement, not the speed of sound. There also is an electro-acoustic
Newtonian motivations for general relativity (2,939 words) [view diff] exact match in snippet view article find links to article
rotation matrix is time dependent, then it does not commute with the time derivative. In that case, the rotation of the separation velocity can be written
Weber electrodynamics (3,093 words) [view diff] exact match in snippet view article find links to article
}}} . Except for the sign, the right-hand side corresponds to the time derivative of the kinetic energy. This means that every change of the potential
Simple wave (1,032 words) [view diff] exact match in snippet view article find links to article
{\partial u}{\partial x}}=0.} Further, since (remember that the time derivative of a function f(x,t){\displaystyle f(x,t)} integrated along a curve
Quantum LC circuit (6,688 words) [view diff] exact match in snippet view article find links to article
variable where the conjugate "momentum" is equal to capacitance times the time derivative of magnetic flux. The conjugate "momentum" is really the charge. π
Crack growth equation (4,677 words) [view diff] exact match in snippet view article find links to article
doi:10.1016/0142-1123(84)90032-X. Pommier, S.; Risbet, M. (2005). "Time derivative equations for mode I fatigue crack growth in metals". International
Magnetorotational instability (4,614 words) [view diff] exact match in snippet view article find links to article
{\displaystyle x} and y {\displaystyle y} directions, and a dot indicates a time derivative (i.e., x ˙ {\displaystyle {\dot {x}}} is the x {\displaystyle x} velocity
Nernst–Planck equation (665 words) [view diff] exact match in snippet view article find links to article
is significant, the equation is further simplified by removing the time derivative of the magnetic vector potential: ∇⋅[D(∇c+zekBTc∇ϕ)]=0{\displaystyle
Frequency selective surface (6,536 words) [view diff] exact match in snippet view article find links to article
quantity k in equations (1.1.1) and (1.1.2) comes originally from the time derivative in Maxwell's equations and is the free space propagation constant (actually
Proprioception and motor control (1,729 words) [view diff] no match in snippet view article find links to article
evidence to suggest that they respond to the force and yank (the first time-derivative of force) exerted on intrafusal muscle. Spindles are also composed
History of microeconomics (9,018 words) [view diff] exact match in snippet view article find links to article
that the dot products Π (between π and the time derivative of z) and B (between E and the time derivative of z) must equal each other. They state: "Except
Method of averaging (4,159 words) [view diff] exact match in snippet view article find links to article
is the coordinates respective to the standard form. If we take the time derivative in both sides and invert the fundamental matrix we obtain x ˙ = ε e
Reassignment method (4,004 words) [view diff] no match in snippet view article find links to article
{D}}h}(t,\omega )} is the short-time Fourier transform computed using a time-derivative analysis window h D ( t ) = d d t h ( t ) {\displaystyle h_{\mathcal
Phonon polariton (2,527 words) [view diff] exact match in snippet view article find links to article
Where w ¨ {\displaystyle {\ddot {\mathbf {w} }}} denotes the double time derivative of w {\displaystyle \mathbf {w} } ϵ 0 {\displaystyle \epsilon _{0}}
Dynamic stall on helicopter rotors (2,710 words) [view diff] exact match in snippet view article find links to article
}}c/V_{\infty }}}} , where α ˙ {\displaystyle {\dot {\alpha }}} is the time derivative of AoA, c {\displaystyle c} is the blade chord, and V ∞ {\displaystyle
Sparse identification of non-linear dynamics (859 words) [view diff] exact match in snippet view article find links to article
defines the equations of motion and constraints of the system. The time derivative may be either prescribed or numerically approximated from the snapshots
Non-topological soliton (6,328 words) [view diff] exact match in snippet view article find links to article
been carried out by Baacke. The quantum energy has been derived as a time derivative of the one-loop fermion effective action S eff = − i ln ⁡ det ( i γ
Cartesian tensor (11,700 words) [view diff] exact match in snippet view article find links to article
names) of continuum mechanics, with another term being the partial time derivative: D D t = ∂ ∂ t + u ⋅ ∇ {\displaystyle {\frac {D}{Dt}}={\frac {\partial
Nano-I-beam (1,123 words) [view diff] exact match in snippet view article find links to article
often made in a moving frame of reference. To account for this, the time derivative of the observed variables in the fixed frame of reference (ρ, θ, z)
Coherent effects in semiconductor optics (4,621 words) [view diff] exact match in snippet view article find links to article
field resulting from the polarization is proportional to its second time derivative, i.e., E∝∂2∂t2P{\displaystyle {\mathbf {E} }\propto {\frac {\partial
Streamline upwind Petrov–Galerkin pressure-stabilizing Petrov–Galerkin formulation for incompressible Navier–Stokes equations (6,999 words) [view diff] exact match in snippet view article find links to article
n ) {\displaystyle z(t_{n})} . Thus, the BDF2 approximation of the time derivative reads as follows: ( ∂ u h ∂ t ) n + 1 ≃ 3 u h n + 1 − 4 u h n + u h
Hamiltonian constraint of LQG (6,931 words) [view diff] exact match in snippet view article find links to article
the integrated densitized trace of the extrinsic curvature is the``time derivative of the volume". The Lagrangian for a scalar field in curved spacetime
General equation of heat transfer (1,893 words) [view diff] exact match in snippet view article find links to article
{v}})-\sigma _{ij}{\partial v_{i} \over {\partial x_{j}}}} Now expanding the time derivative of the total energy, we have: ∂ ∂ t [ ρ ( k + ε ) ] = ρ ∂ k ∂ t + ρ