Plans for week 45, November 3-7

Dear all, welcome back to FYS4480/9480. We hope this week has started the best possible way for you all.

This week we will continue our discussion of many-body perturbation theory and emphasize diagram rules and how to calculate higher contributions. In addition we will also discuss the so-called diagram theorem, which is a very important theorem for several many-body methods, such many-body perturbation theory, coupled cluster theory and Green's function theory. The plan this week is

Thursday:

a. Time-independent perturbation theory: examples of contributions in perturbation theory and diagrammatic representations

b. Diagram rules and their derivations

Friday:

a. Diagram examples

b. Linked diagram theorem

Note: Friday's lecture is a recording only, since I will be attending an all-day workshop, https://www.jus.uio.no/ifp/english/about/organization/nrccl/events/2025/xxxx-nordic-conference-on-law-and-it.html

Exercises week 45 at?https://github.com/ManyBodyPhysics/FYS4480/blob/master/doc/Exercises/2025/Exercisesweek45.pdf

Lecture Material: Whiteboard notes (see above) and Shavitt and Bartlett chapters 5-7

Second midterm

The second midterm will be available from Friday November 14 with deadline November 24. We hope this will not interfere too much with other activities.

Regarding feedback on the first midterm, I had hoped to wrap up it this week, but grading project 1 in FYS-STK took much more time than expected. I am sorry for the delay, we will try to come with feedback early next week, hopefully.

Best wishes to you all,

Morten

p.s. Use the PDF slides for this week, MathJax does not like the usage of additional latex package like simplewick and other.