Term information
In statistical physics, a Langevin equation (Paul Langevin, 1908) is a stochastic differential equation describing the time evolution of a subset of the degrees of freedom. These degrees of freedom typically are collective (macroscopic) variables changing only slowly in comparison to the other (microscopic) variables of the system. The fast (microscopic) variables are responsible for the stochastic nature of the Langevin equation. ... Let A={Ai} denote the slow variables. The generic Langevin equation then reads \frac{dA_{i}}{dt}=k_{B}T\sum\limits_{j}{\left[ {A_{i},A_{j}}\right] \frac{{d}\mathcal{H}}{{dA_{j}}}}-\sum\limits_{j}{\lambda _{i,j}\left( A\right) \frac{d\mathcal{H}}{{dA_{j}}}+}\sum\limits_{j}{\frac{d{\lambda _{i,j}\left(A\right) }}{{dA_{j}}}}+\eta _{i}\left( t\right). source: http://en.wikipedia.org/wiki/Langevin_equation
<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"> <mrow> <mfrac> <mrow> <mi>d</mi> <mo>⁢</mo> <msub> <mi>A</mi> <mi>i</mi> </msub> </mrow> <mrow> <mi>d</mi> <mo>⁢</mo> <mi>t</mi> </mrow> </mfrac> <mo>=</mo> <mrow> <mrow> <mrow> <msub> <mi>k</mi> <mi>B</mi> </msub> <mo>⁢</mo> <mi>T</mi> <mo>⁢</mo> <munder> <mo>∑</mo> <mi>j</mi> </munder> <mo>⁢</mo> <mrow> <mfenced close="]" open="["> <mfenced close="" open=""> <msub> <mi>A</mi> <mi>i</mi> </msub> <msub> <mi>A</mi> <mi>j</mi> </msub> </mfenced> </mfenced> <mo>⁢</mo> <mfrac> <mrow> <mi>d</mi> <mo>⁢</mo> <mi mathvariant="script">ℋ</mi> </mrow> <mrow> <mi>d</mi> <mo>⁢</mo> <msub> <mi>A</mi> <mi>j</mi> </msub> </mrow> </mfrac> </mrow> </mrow> <mo>-</mo> <mrow> <munder> <mo>∑</mo> <mi>j</mi> </munder> <mo>⁢</mo> <mrow> <mrow> <mrow> <msub> <mi>λ</mi> <mfenced close="" open=""> <mi>i</mi> <mi>j</mi> </mfenced> </msub> <mo>⁢</mo> <mfenced close=")" open="("> <mi>A</mi> </mfenced> </mrow> <mo>⁢</mo> <mfrac> <mrow> <mi>d</mi> <mo>⁢</mo> <mi mathvariant="script">ℋ</mi> </mrow> <mrow> <mi>d</mi> <mo>⁢</mo> <msub> <mi>A</mi> <mi>j</mi> </msub> </mrow> </mfrac> </mrow> <mo>+</mo> </mrow> <mo>⁢</mo> <munder> <mo>∑</mo> <mi>j</mi> </munder> <mo>⁢</mo> <mfrac> <mrow> <mi>d</mi> <mo>⁢</mo> <mrow> <msub> <mi>λ</mi> <mfenced close="" open=""> <mi>i</mi> <mi>j</mi> </mfenced> </msub> <mo>⁢</mo> <mfenced close=")" open="("> <mi>A</mi> </mfenced> </mrow> </mrow> <mrow> <mi>d</mi> <mo>⁢</mo> <msub> <mi>A</mi> <mi>j</mi> </msub> </mrow> </mfrac> </mrow> </mrow> <mo>+</mo> <mrow> <msub> <mi>η</mi> <mi>i</mi> </msub> <mo>⁢</mo> <mfenced close=")" open="("> <mi>t</mi> </mfenced> </mrow> </mrow> </mrow> </math>
\frac{dA_{i}}{dt}=k_{B}T\sum_{j}{[ {A_{i},A_{j}}] \frac{{d}\mathcal{H}}{{dA_{j}}}}-\sum_{j}{\lambda _{i,j}\left( A\right) \frac{d\mathcal{H}}{{dA_{j}}}+}\sum_{j}{\frac{d{\lambda _{i,j}\left(A\right) }}{{dA_{j}}}}+\eta _{i}\left( t\right)
<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"> <semantics> <mrow> <mfrac> <mrow> <mi>d</mi> <msub> <mi>A</mi> <mi>i</mi> </msub> </mrow> <mrow> <mi>d</mi> <mi>t</mi> </mrow> </mfrac> <mo>=</mo> <msub> <mi>k</mi> <mi>B</mi> </msub> <mi>T</mi> <munder> <mo>∑</mo> <mi>j</mi> </munder> <mrow> <mfenced close="]" open="["> <mrow> <msub> <mi>A</mi> <mi>i</mi> </msub> <mo>,</mo> <msub> <mi>A</mi> <mi>j</mi> </msub> </mrow> </mfenced> <mfrac> <mrow> <mi>d</mi> <mi mathvariant="script">ℋ</mi> </mrow> <mrow> <mi>d</mi> <msub> <mi>A</mi> <mi>j</mi> </msub> </mrow> </mfrac> </mrow> <mo>-</mo> <munder> <mo>∑</mo> <mi>j</mi> </munder> <mrow> <msub> <mi>λ</mi> <mrow> <mi>i</mi> <mo>,</mo> <mi>j</mi> </mrow> </msub> <mfenced close=")" open="("> <mi>A</mi> </mfenced> <mfrac> <mrow> <mi>d</mi> <mi mathvariant="script">ℋ</mi> </mrow> <mrow> <mi>d</mi> <msub> <mi>A</mi> <mi>j</mi> </msub> </mrow> </mfrac> <mo>+</mo> </mrow> <munder> <mo>∑</mo> <mi>j</mi> </munder> <mfrac> <mrow> <mi>d</mi> <mrow> <msub> <mi>λ</mi> <mrow> <mi>i</mi> <mo>,</mo> <mi>j</mi> </mrow> </msub> <mfenced close=")" open="("> <mi>A</mi> </mfenced> </mrow> </mrow> <mrow> <mi>d</mi> <msub> <mi>A</mi> <mi>j</mi> </msub> </mrow> </mfrac> <mo>+</mo> <msub> <mi>η</mi> <mi>i</mi> </msub> <mfenced close=")" open="("> <mi>t</mi> </mfenced> </mrow> <annotation encoding="SnuggleTeX">\[ \frac{dA_{i}}{dt}=k_{B}T\sum_{j}{[ {A_{i},A_{j}}] \frac{{d}\mathcal{H}}{{dA_{j}}}}-\sum_{j}{\lambda _{i,j}\left( A\right) \frac{d\mathcal{H}}{{dA_{j}}}+}\sum_{j}{\frac{d{\lambda _{i,j}\left(A\right) }}{{dA_{j}}}}+\eta _{i}\left( t\right) \]</annotation> </semantics> </math>
Langevin
LD simulation
LD
LD simulations
Langevin Dynamics Simulation
Langevin dynamics
LD propagation
Langevin Dynamics Simulations
Term relations
- differential equation
- describes some motion and has_quality some stochastic quality
- has_part_equation some Poisson bracket equation and has_variable some (
variable and
is_about some force)