# PHY 622 & 623 String Theory I & II

## F'19, MWF 9:00-53 (ESS 069)
— S'20, MWF 10:00-53
(ESS 181)

#### office consultation available on request

This is a two-semester course.
The course is taught by all of us;
we sit in each other's lectures, and encourage discussions with students.
String theory is a vast subject, so it is not possible to cover all areas.
We give simple introductions to the main areas;
the lectures are self-contained.
We do not use phrases like "It can be shown that...", but rather do all derivations and calculations explicitly.

This year we will begin teaching another revised version of the string course.
As such, the following is a tentative description, subject to revision.

The first semester of the string course was taught in parallel to a 680 course that covered some "prerequisite" material. We recommend @ least sitting in on that course if you lack a sufficient background in any of the topics of
- Yang-Mills
- BRST
- general relativity
- supersymmetry
- supergravity

@ a more elementary level, we also assume some familiarity with the material of the core courses. Quantum field theory is *not* a prerequisite, but we will apply (relativistic) quantum *mechanics* to first-quantization of strings, & to S(cattering)-matrices.
So you should already know, @ least @ an undergraduate level,

- special relativity
- quantum mechanics
- particle physics

### Student participation

We demand questions from students. If you remain silent, we have no way of knowing how well you are following. It does you no good to complain only on the course evaluations (although that may help future students). If you're buying a car, & take it out for a test drive, but use only the gas pedal & not the brake, you can't complain to the salesman afterward that it goes too fast.
### Grading: S/U

Grading is S/U, determined completely by the final exam, which is part written & part oral.
There will also be frequent homeworks, mainly for you to monitor your progress.
### Textbook: Free typed notes are distributed

### First semester

- free bosonic strings
- What are strings?
- action
- quantization
- spectrum

- free spinning strings
- extensions of the results of the free bosonic string (see above)
- types of superstrings

- T-duality: Buscher rules
- compactification
- supersymmetric vacua
- branes

- interacting strings
- Regge theory
- 1st-quantized S-matrices
- string tree graphs

- Green-Schwarz approach

### Second semester

- covariant quantization
- ghosts & BRST charge
- 2D (super)conformal field theory
- D = 26 or 10

- more compactification: differential geometry
- S-duality in supergravity: weak ↔ strong coupling
- more scattering
- picture changing
- tree graphs in spinning string theory
- loops

- Anti-de Sitter/Conformal Field Theory

## On-line lecture notes, etc.

### Siegel

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##### University-required statements

These statements are required in all University syllabi. (They are the same in all course syllabi, so just read it once.)