L21.3 Integral equation for scattering and Green's function

[@yomboh7033]

とても分かりやすくて感動致しました。非常に大らかかつ表現性のある喋り方で、心地よく内容を理解することができました。 I was really moved by the informative expression by Barton Zwiebach! He speaks in really fun and informative way which is easy to understand for me Japanese.

[@him31anshu]

I have been looking for this for 3 years!! It was here all the time!

[@physicsboy3108]

Really he had mastered Quantum Mechanics in present era of physics!!!

[@Higgsinophysics]

Helped me a lot - thanks for the upload

[@dpavlovsky]

Excellent explanation. Thank you for the upload.

[@ey3796]

Bro could you explain the phase approximation done at 27:00?, Cheers.

[@skipperglume]

@@ey3796 It was done just to have an approximation for small r primes in compare to r.

[@Kathie-ov8lv]

​​​​@@ey3796 n is the unit vector in the r direction. For a small angle between r' and r (which occurs for r >> r'), projection of r' on the r direction (n.r') is approximately equal to r' itself. Thus we write |r - r'| as approximately equal to |r - n.r'| in the numerator where this term is being multiplied by "k" to keep the possible error under control (instead of writing |r-r'| ~ r as we did for the denominator). And why do we need such an approximation instead of leaving r' just as r'? It is to connote the relation between r and r' instead of treating them as two totally irrelevant vectors/objects in our equation (which would dampen the information we get from the solution).

[@huitang1853]

Easy to understand, thx!

[@vikashkumarmukhia3013]

Equivalent to Griffith solution

[@not_amanullah]

Thanks 🤍❤️

[@ananddaawar4741]

String theorist explains pretty well! I thought it would short circuit me xD

[@justicepatrick6366]

i guess I am pretty off topic but does anybody know a good site to stream newly released series online?

[@joeltrevor3257]

@Justice Patrick flixportal :D

[@justicepatrick6366]

@Joel Trevor Thank you, signed up and it seems like they got a lot of movies there :D Appreciate it !

[@joeltrevor3257]

@Justice Patrick happy to help xD

[@not_amanullah]

This is helpful ❤️🤍