Beskjeder
Dear all, the last week was our last official week of lectures. However, since we have our deadline for the second midterm on Monday the 5th of December, we thought of meeting at our regular time on Friday and we can have a session 915am-12pm if everybody is fine with that. We can discuss the midterm and other topics as well. This is Friday the 2nd of December, starting at 915am.
We plan to have a similar session on Friday the 15th, before our final oral examinations The week thereafter, week 50, that is from Monday the 19th to Thursday the 22nd, we are planning our oral exams. Please do send us your constraints about preferred times etc.
Best wishes to you all,
Morten and ?yvind
Dear all,
due to the school on quantum computing with many of you attending it, the lectures Thursday 1015am-12pm and Friday 1015am-12pm will be recorded only. However, for those of you who can be there, we plan to discuss the second midterm (due December 5 at midnight) 815am-10am. The second midterm is available at https://github.com/ManyBodyPhysics/FYS4480/blob/master/doc/Exercises/2022/SecondMidterm2022.pdf
The videos will be added asap.
The topics to be covered are thus
### Week 46, November 14-18, 2022
- Topics to be covered
- Thursday lecture 10am-12pm (recording only):
- Summary many-body perturbation theory and discussion of Coupled Cluster theory
- Video of lecture to be added
- Friday Lecture 10am-12pm (recording only):...
Hi all,
last week we continued our discussion of many-body perturbation theory, with diagrammatic examples as well as starting a discussion of time-dependent theory. We will continue with time-dependent theory and discussion of diagrams this week as well before we move on to Coupled cluster theory, which is our last many-body method covered in this semester.
In connection with time-dependent many-body theory we will also discuss the adiabatic hypothesis and the linked diagram theorem and so-called unlinked diagrams.
The plans for this week are
Lecture Thursday:
-Adiabatic hypothesis and linked diagram theorem. Slides at https://github.com/ManyBodyPhysics/FYS4480/blob/master/doc/pub/week45/pdf/slidesweek45.pdf
-Examples of diagrams and discussion of Pauli violating diagrams. Handwritten notes and discussion of exercise 1, week 45
...
Hi all,
last week we started discussing many-body perturbation theory.
This week we continue this discussion and the aim is
Lecture Thursday:
o Time-independent perturbation theory and diagrammatic representation
o Examples of contributions to perturbation theory
Lecture Friday
o Discussion of the Heisenberg, Schroedinger and Interaction pictures
o Time-dependent perturbation theory and diagrammatic representation, Pauli-violating diagrams
o Linked-diagram theorem
Lecture Material: Handwritten notes and Shavitt and Bartlett chapter 4-6
Eight exercise set for Friday at https://github.com/ManyBodyPhysics/FYS4480/blob/master/doc/Exercises/2022/ExercisesWeek44.pdf
Best wishes to you all,
Morten and ?yvind
Dear all, the aim this week is to get started with many-body perturbation theory, starting with a time-independent derivation and thereafter moving to a diagrammatic representation and time-dependent perturbation theory. We start on Thursday by linking FCI theory and Hartree-Fock with many-body perturbation theory by reminder ourselves about Thouless' theorem. The exercise this week is (perhaps) a final word on the Lipkin model with applications of Hartree-Fock theory to the model plus a discussion of the stability of the Hartree-Fock method in terms of the interaction strength parameters.
The plan for the week is as follows:
* Topics to be covered
o Thursday:
* Linking FCI and Hartree-Fock theory with many-body perturbation theory
* Time-independent perturbation theory
o Friday:
* Time-dependent perturbation theory and diagra...
Dear all,
this week we will wrap up our discussions of Hartree-Fock theory, see the slides for week 42 at https://manybodyphysics.github.io/FYS4480/doc/pub/week42/html/week42-bs.html on Thursday. Here we will discuss the stability of the Hartree-Fock equations and how to solve the equations numerically. On Friday we will mainly discuss the first midterm. The next topic, many-body perturbation theory will be postponed by one week to week 43. The discussion of the numerical implementation of the Hartree-Fock method is relevant for the last part of the first midterm.
Best wishes for the week,
Morten and ?yvind
Dear all, this week due to travel, the lecture on Thursday will be recorded only. The video will be uploaded by Thursday and a mail will be sent to you all for the link to the video. It will also be posted under the schedule link. On Friday we plan to work on the first midterm only. Thus there is no lecture this coming Friday, only work on the first midterm.
The plan for the week is as follows:
- Topics to be covered
- Thursday:
- Repetition of derivation of Hartree-Fock theory
- Stability of Hartree-Fock theory and Thouless theorem
- "Video of lecture":"https://youtu.be/"
- Friday:
- Work on first midterm
- Lecture Material: Lecture slides week 41, handwritten notes and Szabo and Ostlund, chapter 3
- First midterm set at https://github.com/ManyBodyPhysics/FYS4480/blob/master/doc/Exercises/2022/FirstMidterm2022.pdf
Dear all, from last week, we have changed from the 'smelly' room F?257 to F?467, permanently for the rest of the semester.
Hi all, we hope all is well!
Last week we discussed full configuration interaction theory and linked this with the usage of Wick's theorem and the calculation of explicit matrix elements (between many-body states with Slater determinants as basis states/computational basis). The wisdom is that if we can set up the so-called Hamiltonian matrix and diagonalize the problem, then this should provide us with all eigenpairs and in principle (although we may have truncated severely our Hilbert space) we should have solved the problem. If not, we need to deal with approximative methods. Our first method is Hartree-Fock theory, where we reduce the many-body problem to a set of coupled single-particle equations. We will see also that this corresponds to a unitary transformation of the Hamiltonian matrix where we zero out the matrix elements that connect the 0p0h block with the 1p1h block.
The plan for this week is thus:
===== Week 40, October 3-7, 2022 =====...
Hi everybody, we hope the week has started the best possible way.
Last week we discussed the so-called particle-hole formalism nd we used that to rewrite our basis of Slater determinants in terms of particle-hole excitations. The material is covered by Shavitt and Bartlett chapters 3 and 4 and the lecture notes.
This week the plan is
Topics to be covered
Thursday:
Repetition of particle-hole formalism
Diagrammatic representation
Introduction of full configuration interaction theory
Friday:
Full configuration interaction (FCI) theory
Lipkin model as an example of applications of FCI theory
Lecture Material: These slides, handwritten notes and for the diagrammatic representation, Shavitt and bartlett chapter 4.
Fifth exercise set at https://github.com/ManyBodyPhysics/FYS4480/blob/master/doc/Exercises/2022/ExercisesWeek39.pdf
Best wishes to you all,
Morten and ?yvind
Welcome back to you all.
Last week we summarized our discussions on Wick's theorem, with a discussion of what is called the generalized Wick's theorem as well. Thereafter we moved over to a diagrammatic representation.
We worked also on an exercise based on a simplified model called the Lipkin model. This model will follow us in this course as it allows us to illustrate many important aspects of many-body theories. We will encounter it again when we discuss full configuration interaction theory, Hartree-Fock theory and other many-body theories. Lately it has been used in applications of algorithms for quantum computing as well.
The exercises for this week contain a follow-up exercise based on the Lipkin model from last week. Feel free to continue working on the Lipkin model this week as well, in addition to the two other exercises this week, see
https://github.com/ManyBodyPhysics/FYS4480/blob/master/doc/Exercises/2022/ExercisesWeek38.pdf...
Dear all,
this week we will have our exercise session on Thursday. We will continue partly with these exercises on Friday and thereafter we dive into Wick's theorem and the particle hole formalism.
The week is thus going to be approximately like this:
- Topics to be covered
- Thursday: Exercises for week 37
- Friday: Wrappping up Wick's theorem, Wick's generalized theorem and diagrammatic representation, Particle-hole formalism and definition of new reference state, normal ordering of operators. Video of lecture will be posted right after the lecture.
- Lecture Material: Lecture slides for week 37 at https://manybodyphysics.github.io/FYS4480/doc/pub/week37/html/week37-bs.html, handwritten notes and chapter 3 of Shavitt and Bartlett covers most of the material discussed this week.
- Third exercise set (Thursday this week) at ...
Hi all, this week we cover in more depth second quantization and how to represent operators as well as deriving and proving Wick's theorem.
The lecture notes are at https://manybodyphysics.github.io/FYS4480/doc/pub/week36/html/week36-bs.html
The second exercise set is at https://github.com/ManyBodyPhysics/FYS4480/tree/master/doc/Exercises/2022 and you will also find the solutions to the previous exercise set (week 35) in the same folder. The material on Wick's theorem is presented at the link for the handwritten notes, see https://github.com/ManyBodyPhysics/FYS4480/tree/master/doc/HandwrittenNotes/2022
See also Szabo and Ostlund sections 2.3 and 2.4
Best wishes to you all,
Morten and ?yvind
This week we discuss the calculation of expectation values of one-body and two-body operators using what is called first quantization. This material will be the topic for Thursday's lecture (September 1). This topic will also serve as a motivation for introducing second quantization, which we start with on Friday.
The material is covered by the lecture notes at https://manybodyphysics.github.io/FYS4480/doc/pub/secondquant/html/secondquant-bs.html.
The material during the first two weeks (August 22-September 2) is well covered by chapters 1 and 2 of Szabo and ?stlund, see https://github.com/ManyBodyPhysics/FYS4480/blob/master/doc/Literature/szaboostlund.pdf.
As a reminder, the lectures are recorded and you will find the link to the lectures at this site under schedule and also at the jupyter-book of the lectures and the readme file of the main github site of the course, see https://github.com/Man...
Dear all, we will use Fridays first two hours for discussing exercises.
However, since this is the first week, there are no exercises and we start with a regular lecture at 10.15. The video from yesterday's lecture is at https://youtu.be/ScHgSRCmq-0, with subtitles.
If you cannot attend in person, the zoom link is
Topic: FYS4480 Lectures
Time: This is a recurring meeting Meet anytime
Join Zoom Meeting
https://msu.zoom.us/j/96498598694?pwd=MmNUTk1POFFaSFpzelUxSENJMUJOZz09
Meeting ID: 964 9859 8694
Passcode: 498901
All lectures will be recorded and posted after the lectures. The handwritten notes are at https://github.com/ManyBodyPhysics/FYS4480/tree/master/doc/HandwrittenNotes/2022
All material from the lectures and pertinent to the lectures is at the Github address of course, https:...