Hot answers tagged brownian-motion
5
The article makes no sense. Einstein realized that matter was composed out of atoms, so the number of collisions of a Brownian particle with the surrounding molecule is finite in a finite period of time.
However, for times $t$ much longer than the typical scale between the collisions, the particle moves by a distance scaling like $\sqrt{t}$. It follows that ...
4
There are tons of papers on the connection between quantum processes and probability theory (though I don't understand why you single out coherent states - they don't play a special role in this connection).
The theory of stochastic processes and the theory of quantum processes are the commutative and noncommutative side of the same coin, with many ...
4
The differential is used to specify that the number is for a "differential range", which is a way to remind you that the notions involved are somewhat fuzzy.
Let me give a purely mathematical example. Suppose I tell you that I am going to pick an arbitrary real number between 0 and 10, with the likely hood of a number being picked being proportional to the ...
4
For Brownian motion, Langevin equation, Fokker-Planck equations, Stochastic process.. from the viewpoint of physicists, the following are standard references:
Brownian Motion: Fluctuations, Dynamics, and Applications
The Fokker-Planck Equation: Methods of Solutions and Applications
Handbook of Stochastic Methods: for Physics, Chemistry and the Natural ...
3
Many different types of connection can be made between stochastic states over commutative algebras of observables and quantum states over noncommutative algebras of observables. As Arnold says, there is a substantial literature.
One approach is to construct both classical and quantum models in a formalism that accommodates both; within the structured ...
1
The equation resembles the heat equation very closely, so much so, that it is the heat equation.
The literature on elementary things like this is uniformly terrible, so I cannot give a reference. To see why it is the heat equation, note that the law for the distribution function is the same as for a probability distribution, so it is linear equation, by the ...
1
This is a bit strange. The Langevin equation
$$
\frac{dv}{dt}~+~\beta v~=~\frac{F}{m}
$$
for the motion of a free particle under a stochastic force $F$ evaluates the velocity as an average or in an interval. The stochastic force has a Gaussian probability distribution $\langle F(t)F(t’)\rangle~=$ $2\beta kT\delta(t~-~t’)$, which is also a Markov ...
Only top voted, non community-wiki answers of a minimum length are eligible