Basics of Quantum Field Theory

H.W. Grießhammer                                                           SS 2004

Last update 22nd July 2004.

My thanks to all of you who attended. Don't forget that QFT is learned by doing calculations, not by listening to lectures.
I hope to see you soon again with your critiques, comments and questions. My door is always open for you.

By the way, with the knowledge acquired, you can now try to understand a good deal of Hawking's abstract at a recent conference in Dublin, where he supposes that no information is lost when you fly into a Black Hole.


Prerequisites: Quantum Mechanics, Relativistic Quantum Mechanics, outline of Quantum Field Theory on the level of ``Quantenmechanik I & II''; particle phenomenology on the level of ``Kerne und Teilchen I & II''; Classical Field Theory and Special Relativity.

Lecture hours: 
                             Mondays 11:00 s.t. to 12:00 s.t. hrs.
                             Wednesdays 13:40 to 15:10 hrs.

No lectures in weeks 3rd to 14th May and 31st May to 4th June.

Co-ordinated with ``Theoretische Hochenergiephysik'' (A. Buras, Tue 11-13 and Thu 10-12), ``Effektive Feldtheorie'' (A. Hoang, Mon 9-11 and Wed 11-13).

Office hours: You are always welcome with questions, discussions, comments and critique, in particular Friday 10-12 in my office: room 3209, Tel. 289-14403, Email hgrie<at>ph.tum.de

Suggested Rough Outline

0. Introduction

Why QFT? - Conventions - Historic overview - Review of Classical Field Theory

1. Canonical Quantisation

Scalar & Dirac field


2. Gauge Theories
         
          Abelian and non-Abelian gauge theories - canonical quantisation

3. Path Integral Quantisation

Motivation from Quantum Mechanics - PIs in QFT - generating functional - Wick's theorem and Feynman rules - Faddeev-Popov quantisation of gauge theories - ghosts and gauge invariance


Detailled Plan:

Lecture date
Topic
Suggested preparatory reading
Mon, 19.4.
Introduction: Setting the value

Wed, 21.4. (only 1 hour)
Introduction: Historical note; Notation

Mon, 26.4.
Introduction: Classical Field Theory: equations of motion Ryder Chap. 3.1 to 3.3;
Kaku Chap. 1
Ramond Chap. 1.5
Wed, 28.4.
SPECIAL PLACE:
SR 3343 (Handbibliothek Physik)
Introduction: Classical Field Theory:
Noether theorem; conserved charges; energy-momentum tensor; solutions for the Klein-Gordon and Dirac fields
dito;
Ramond Chap. 1.6 and 1.7
3. - 14. May no lectures


Wed, 19.5., 13:30hrs (see above) again in SR1141
Canonical quantisation: How to Quantise; free, real scalar fields; Casimir effect
Ryder Chap. 4.1
Kaku Chap. 3.1 and 3.2
Zee Chap I.8 (Casimir effect)
Mon 24.5.
Canonical quantisation: Complex scalar field and Dirac field
Ryder Chap. 4.2 and 4.3
Kaku Chap 3.3, 3.5 and 3.6
Kugo Chap 2.1 and 2.2
Wed 26.5.
Canonical quantisation: Schroedinger Picture; Mathematical Interlude on Functions, Functionals and Functional Differentiation; Wave Function of the Free Scalar Field Ryder Chap. 5.4
The Schroedinger-picture is hard to find in textbooks...
31.5. - 4.6. no lectures


Mon 7.6., 11:00 hrs s.t.
(see above); take crayons with you!
Gauge Theories: Introducing Lie Groups: Flavour-SU(2) revisited
Ryder Chap. 2.3
Chen/Li Chap 4.4
Peskin/Schroeder Chap 15.4
Kugo Chap. 5.1
repeat flavour-symmetry from Kerne-und-Teilchen-lecture!
Wed 9.6., 13:40 hrs s.t. Gauge Theories: Quantum Generators of classical symmetries; Mathematical Interlude on Lie Groups and Lie Algebras see Mon, 7.6.
Mon 14.6., 11:00 hrs s.t.
take crayons with you!
Gauge Theories: From global to local symmetries: the geometry behind non-Abelian gauge fields; Mathematical Interlude on fibre bundles and connections
Ryder Chap. 3.6
Cheng/Li Chap 8.1 and 2
Peskin/Schroeder Chap 15.1
Kugo Chap 5.1
Wed 16.6., 13:40 hrs s.t.
take crayons with you!
Gauge Theories: curvature, field strength and equations of motion; Mathematical Interlude on fibre bundles and connections see Mon, 14.6.
Mon 21.6., 11:00 hrs s.t. Gauge Theories: a dictionary between Physics, Differential Geometry and General Relativity; canonical (constraint) quantisation of Gauge Theories
Kaku Chap. 4.1, 2 and 3;
also in Ryder Chap. 4.4, but we do it differently.
Kugo Chap. 5.2 and 5.5 for the die-hards
Wed 23.6., 13:40 hrs s.t. Gauge Theories: Canonical (constraint) quantisation of  QED, and why it does not work for QCD
Path Integrals: Philosophical Background
see Mon, 21.6.

Zee Chap. 1.2
No lecture Mon 28.6., 11:00 hrs s.t. (taken over by Buras: Theoretische Hochenergiephysik)
see Thu, 1.7.


Wed 30.6., 13:40 hrs s.t. Path Integrals: No derivation of path integrals in Quantum Mechanics: motivation; expectation values; sources
Sakurai: Modern QM, Chap. 2.5
The following presentations do not differ too much from each other:
Ryder Chap. 5; Kaku Chap. 8.1 and 2; Ramond Chap. 2.2; Peskin/Schroeder Chap. 9.1
and for the die-hards: Kleinert: Pfadintegrale; Rivers: Path Integral Methods in Quantum Field Theory.
Thu, 1.7., 10:15-11:45 s.t.  special date (taken over from Buras: Theoretische Hochenergiephysik) Path Integrals: No derivation of path integrals in Quantum Mechanics (cont'd): Wick rotations and Euclidean time, scattering states
see Wed, 30.6.
Kugo Chap. 4.2

Mon 5.7., 11:00 hrs s.t. Path Integrals: PIs in QFT; third mathematical interlude: Gaussian Functional Integration
Kaku Chap. 8.3
Kugo Chap. 4.2
Ryder Chap. 6.2
Wed 7.7., 13:40 hrs s.t. Path Integrals: Generating Functional, free two-point function, deriving Feynman rules; generating functional of connected diagrams
any of the textbooks; you should do exemplary calculations of two-and four-point functions to first order in the coupling in Phi^4-theory. Follow the steps e.g. in Ryder Chap. 6.5;
see also Ramond Chap. 4.1 for a true proof that Feynman rules are rules of differentiation.
That W[J] generates only connected graphs is best shown in Kugo Chap. 4.3.1
Mon 12.7., 11:00 hrs s.t. Path Integrals: deriving Feynman rules (cont'd), LSZ-reduction; Fourth mathematical Interlude; Grassmann variables, differentiation and integration
Ryder Chap. 6.8
Ryder Chap. 6.7
Kaku Chap. 8.6; Ramond Chap. 5.1
Wed 14.7., 13:40 hrs s.t. Path Integrals: Generating Functional for fermions, Faddeev-Popov Quantisation of Non-Abelian gauge Theories Ramond Chap. 5.2 and 3; Ryder Chap. 6.7
Cheng/Li Chap. 9; Ryder Chap. 7.2
Mon 19.7., 11:00 hrs s.t. Path Integrals:Faddeev-Popov Quantisation of Non-Abelian gauge Theories (cont'd) see above
Wed 21.7., 13:40 hrs s.t. Path Integrals: BRST-symmetry/Slavnov-Taylor identities Ryder Chap. 7.4,5 and 6

Some Books:

The ``books to the lecture'':

0. A. Zee: Qunatum Field Theory in a Nutshell; Princeton University Press, 50 Euro. (NEW: Test it and tell me how you like it.)
1. Lewis H. Ryder: Quantum Field Theory, 2nd ed.; Cambridge University Press, 55 Euro.
2. Michio Kaku: Quantum Field Theory; Oxford University Press, 55 Euro.
3. Pierre Ramond: Field Theory: A Modern Primer, 2nd ed.; Addison Wesley, 55 Euro.
4. Michael E. Peskin and Daniel V. Schroeder: An Introduction to Quantum Field Theory; Addison Wesley, 77 Euro.

Classics and Modern Classics:
5. Steven Weinberg: The Quantum Theory of Fields, Vol. 1 and Vol. 2; Cambridge University Press, 65 Euro each.
6. James D. Bjorken and Sidney D. Drell: Relativistic Quantum Mechanics; McGraw Hill, 55 Euro. Also in German.
7. James D. Bjorken and S. D. Drell: Relativistic Quantum Fields; McGraw-Hill, 55 Euro. Also in German.
8. Claude Itzykson and Jean-Bernard Zuber: Quantum Field Theory; McGraw-Hill, 70 Euro.

``The price is right'':
9. Waren Siegel: Fields; http://insti.physics.sunysb.edu/~siegel/plan.html, free.

Only in German:
10. Taichiro Kugo: Eichtheorie; Springer, 60 Euro.

More applied to high-energy Phsyics:
11. Ta-Pei Cheng and Ling-Fong Li: Gauge Theory of Elementary Particle Physics; Oxford University Press, 95 Euro.
12. Taizo Muta: Foundations of Quantum Chromodynamics: An Introduction to Perturbative Methods in Gauge Theories; World Scientific Lectures Notes in Physics, 95 Euro.