**Fields v4**contains the lecture notes for the class.- ⚠️ This book and web page are being revised
*during*the course. - It may help to have a copy of the relevant subsections available during class (preferably in digital form) for annotation, or help in asking questions (especially prepared ones).

- ⚠️ This book and web page are being revised
**Assigned reading**is crucial for you to prepare questions ahead of class.- It includes @ least 2 subsections ahead of lecture (including the homework problems to be assigned).
- Skim the background material to see if you need it.
- Also note the summaries given in the
**Outline**@ the beginning of the book, & for equations the**AfterMath**@ the end. - If you miss or are late to class, you are responsible for any material you missed: See me in private or ask fellow students.

**Homework**is essential to help you understand the lecture, & as preparation for the exams.- It's due 1 week after reached in lecture, @ beginning of class, & returned @ the beginning of the following class.
- You can submit it on paper in class, or electronically; if on paper, don't turn in different assignments on the same sheet or you won't get it back till the latest is returned.
- Late homework is not accepted.
**There will be some discussion of the homework in class**, @ the beginning of the lecture when it's returned. More hints will be given for problems students had difficulties with, but not all the algebra will be worked out. You are encouraged to give a second try on problems you failed to complete, for your own edification (not for turning in).

Topology | in subsections | background material & homework |
---|---|---|

graph topology | ||

- P−V = L−1
| VC2 (last ⅕) | |

group theory via graphs | IB1 (matrices), IC4 (color & flavor) | |

- index lines
- Feynman graphs
| VC9 | VC9.1 (due 10/28) |

1/N_{color} expansion | ||

- color loops
- Euler number
- flavor
| VIIC4 | |

worldsheet topology | ||

- duality
- tadpoles
- open→closed
| XIA2 | XIA2.1 (due 11/1) |

discrete worldline symmetries | IA4 (proper time) | |

- CPT
- worldline/spacetime
| IA5 | |

string theory typology | IB4-5 (SO/Sp groups) | |

- Chan-Paton
- worldsheet CPT
- orientation
- supersymmetry
| XIA4 | XIA4.1 (due 11/4) |

Geometry | ||

particle propagators | IIIA1 (Dirac δ), IIIB (classical), VA3 (nonrelativistic) | |

- proper time
- iε ℞
- energy sign
| VB1 | VB1.1 (due 11/6) |

1st-quantized particle graphs | ||

- Schwinger parameters
- 1st-q action
| VC8 | |

worldsheet lattices | VA5,VB4 (Wick rotation) | |

- discrete worldsheet
- string action
- preon propagators
| XIA7 (1st ½) | XIA7.1 (due 11/6) |

Particle scattering | ||

1st-q S-matrices | IIIB3 (background fields), VA4 (nonrelativistic) | |

- perturbation
- interaction picture
- Green function
- loops
| VIIIC5 | |

Γ functions | ||

- Schwinger parametrization
- Beta function
| VIIA2 | VIIA2.2,3, VIIC2.2 (due 11/11) |

Coulomb scattering | IA4 (Mandelstam variables), VA2 (JWKB) | |

- eikonal approximation
- strong coupling
- infrared
| VIIA6 (2nd ½) | VIIA6.2 (due 11/13) |

String trees | ||

Regge behavior | ||

- ladders
- complex angular momentum
- duality
| XIA1 | XIA1.2 (due 11/15) |

Green functions | ||

- cylinder→plane
- closed→open
| XIB2 (last ⅖) | VIIB1.1 (due 11/15) |

Open trees | ||

- 4 tachyons
- limits
- higher-point
| XIB6 | XIB6.2 (due 11/18) |

Closed trees | ||

- Schwinger parameters
- 4 tachyons
- open factorization
| XIB7 | XIB7.1,2 (due ...) |

Green-Schwarz | ||

superparticle | IIC1-2 (supersymmetry), IIIB1-2 (scalar particle) | |

- Hamiltonian
- constraints
- lightcone gauge
| IIIB6 | IIIB6.1 (due ...) |

superstring | XIA5 (T-duality) | |

- currents
- action
- lightcone gauge
| XIA9 |