Add formulas for distributions (#69690)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/69690
* #69558
Test Plan: Imported from OSS
Reviewed By: albanD
Differential Revision: D33031726
Pulled By: soulitzer
fbshipit-source-id: 9ae461dc6043d48d5bb8c2bbaa266d06ad99f317
