$$\frac{\mathrm df}{\mathrm dt} = \left(\frac{\partial f}{\partial t}\right)_\text{force}+\left(\frac{\partial f}{\partial t}\right)_\text{diff}+\left(\frac{\partial f}{\partial t}\right)_\text{coll}$$

where the "force" term is the external force, the "diff" term represents the diffusion of particles, and "coll" is the collision term. Source: https://en.wikipedia.org/wiki/Boltzmann_equation

So shouldn't $\frac{\mathrm df}{\mathrm dt}$ be 0 when it is not just collisionless but also force and diffusion must go to zero too?


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.