Langevin equation (corrected)

[@nicolaszou6809]

The equation presented in 29:48 is not Fokker-Planck equation, and if you put the solution into this equation, you would find the two sides are not equal when you calculate very carefully. This mistake is on derivation. Please check and your video is very useful, thanks a lot!

[@josthijssen6782]

You are right. The first v on the rhs should be inside the derive. I'll have a closer look at it and post a corrected version.
Thanks!

[@Non-Hypocrite]

Thanks Jos, you make it very simple.

[@MrJOSETACO]

This was very good, much appreciated! Do you post the notes for this lecture/vid anywhere online?
-brad

[@josthijssen6782]

+bp Dear Brad, Thank you for your kind words. I have uploaded the tablet notes used for all my videos on stat mech (not the ones on classical mechanics, though) to github.com/josthijssen/TabletNotes

[@MrJOSETACO]

+Jos Thijssen Awesome! Much appreciated..I've been struggling with a few of these derivations, your notes/lecture have made them trivial at this point.

[@damian.gamlath]

very clear - many thanks :)

[@robsenponte3308]

Nice video

[@MoraAbbasi]

thank you. but why did you consider t1 and t2 equal?

[@josthijssen6782]

Thanks for your question. Which minute/second are you writing about? If you mean the discussion after 17:00 minutes, it is due to the property of the Langevin forces,

[@MoraAbbasi]

thank you so much professor
@@josthijssen6782

[@aniruddhabose5315]

How can we model the random force so that I can write some code for it. ????
Appreciate your videos !!!!

[@josthijssen6782]

You just choose a random value for it at each timestep with the property that = q \delta_{nm}/\Delta t

[@tomsmith6878]

@20:28 q = 6 * gamma * k * T

[@josthijssen6782]

The factor 6 is indeed correct for 3D. Here I consider 1D to keep it simple; for 1D, the factor 2 is correct.