University of Illinois at Urbana-Champaign · Department of Physics

Physics 483

General Field Theory

Fall Semester 2003

Instructor: Professor Eduardo Fradkin


Department of Physics
University of Illinois at Urbana-Champaign
Room 2119 ESB, MC-704,
1110 W Green St, Urbana, IL 61801-3080
Phone: 217-333-4409
Fax: 217-333-9819
E-mail efradkin@uiuc.edu
Eduardo Fradkin's Homepage

Time: 2:30pm-3:50 Tuesday-Thursday
Place: Rm. 158 Loomis
Office Hours: Wednesdays 4:00pm-5:00pm, Rm 2119 ESB
Credit: 1 unit.
Call Number: 06701

TA: Ms. Eun-Ah Kim
Office Hours: Mondays, 4:00pm-5:00pm, Rm 3101 ESB
Phone: 333-6276
E-mail: eunahkim@uiuc.edu





In many areas of Physics, such as High Energy Physics, Gravitation, and in Statistical and Condensed Matter Physics, the understanding of the essential physical phenomena requires the consideration of the collective effects of a large number of degrees of freedom. Quantum Field Theory is the tool as well as the language that has been developed to describe the physics of problems in such apparently dissimilar fields.

Physics 483 is the first half of a two-semester sequence of courses in Quantum Field Theory. The second half, Physics 485, will be taught in the Spring Semester. The aim of this sequence is to provide the basic tools of Field Theory to students (both theorists and experimentalists) with a wide range of interests in Physics. These ideas and tools will be used in subsequent and more specialized courses. As a prerequisite I will assume that the students have mastered the contents of the Physics 480/481 sequence on Quantum Mechanics (or equivalent).
In Physics 483 we will study the basic conceptual and computational tools of quantum field theory. We will discuss the applications of these methods to several areas of Physics, such as High Energy and Statistical and Condensed Matter Physics, both in the Lectures and in the Problem Sets.

In Physics 485 we will discuss advanced topics including Gauge Theories, the Renormalization Group in Field Theory and in Statistical Physics, non-perturbative methods in QFT (solitons and instantons), elementary Conformal Field Theory and its applications to String Theory and Critical Phenomena, and QFT, Topology and quantum Hall physics.
Below you will find a detailed Course Plan (or Syllabus) for Physics 483. It is divided in items and there you will find links to my class notes. I will post them as they become available. You will also find links to the homework sets and to their solutions. There will be a total of six homework sets (more or less). The homworks are very important. There you will find many applications to different problems in various areas of Physics in which Field Theory plays an essential role. You will not be able to master the subject unless you do (and discuss) the problem sets. There will not be a midterm exam but there will be a Final Exam.

You can access the Physics 483 Gradebook here


Announcements


Homeworks:

Homework Set No. 1 pdf file; Posted: 9/2/2003; Due : 9/19/2003

Solutions to homework set 1; Posted: 10/6/2003

Homework Set No. 2 pdf file; Posted: 9/18/2003; Due : 10/3/2003

Solutions to homework set 2; Posted:10/28/2003

Homework Set No. 3 pdf file; Posted: 10/6/2003; Due : 10/20/2003

Solutions to homework set 3; Posted:11/5/2003

Homework Set No. 4 pdf file; Posted: 10/20/2003; Due : 10/31/2003

Solutions to homework set 4;Posted:11/21/2003

Homework Set No. 5 pdf file; Posted: 10/31/2003; Due : 11/10/2003

Solutions to homework set 5;Posted:12/10/2003

Homework Set No. 6 pdf file; Posted: 11/12/2003; Due : 11/22/2003

Solutions to homework set 6;Posted:12/15/2003

Homework Set No. 7, Take Home Final Exam pdf file; Posted: 12/9/2003; Due : 12/19/2003

Course Plan

Introduction to Quantum Field Theory ( pdf file), updated 9/2/2003

Classical Field Theory: ( pdf file ), updated: 10/10/2003
Fields, Lagrangians and Hamiltonians. The action. Real and complex fields. Space-Time and Internal symmetries. The Least Action Principle. Field Equations. Minkowski and Euclidean spaces.
The free massive relativistic scalar field. The Klein Gordon Equation, its solutions and their physical interpretation. Relativistic Covariance.
Statistical Mechanics as a Field Theory. Coarse graining and hydrodynamic picture. The Landau Theory of Phase Transitions and Landau functionals. Symmetries. Analogy with the Klein-Gordon field.
Field Theory and the Dirac Equation. The Dirac Equation: The Dirac and the Klein Gordon operators. Spinors. The Dirac Algebra. Relativistic Covariance. Solutions and their physical interpretation. Symmetries. Holes. Massless particles and chirality.
Maxwell's Electrodynamics as a Field Theory. Maxwell's Equations. Gauge invariance. Solutions and gauge fixing. Helicity.
Classical Field Theory in the Canonical Formalism. Analytic Continuation to imaginary time and the connection between Quantum Field Theory and Classical Statistical Mechanics.

Symmetries and Conservation Laws ( pdf file ), updated: 10/10/2003

Continuous Symmetries, Conservation Laws and Noether's Theorem.
Internal Symmetries. Global Symmetries and Group Representations. Local Symmetries and Gauge Invariance. Non-Abelian Gauge Invariance. Minimal Coupling.
The role of topology: the Aharonov-Bohm effect.
Space-Time Symmetries and the Energy-Momentum Tensor. The Energy-Momentum tensor and the geometry of space-time.

Canonical Quantization ( pdf file ), updated: 10/2/2003

Elementary Quantum Mechanics.
Canonical Quantization in Field Theory.
A simple example: Quantized elastic waves.
Quantization of the Free Scalar Field Theory.
Symmetries of the Quantum Theory: the case of the free charged scalar field.

Path Integral Quantization in Quantum Mechanics and in Quantum Field Theory ( pdf file ), updated: 10/16/2003

Path Integrals and Quantum Mechanics. Density matrix.
Evauating Path Integrals in Quantum Mechanics
Path Integral quantization of the Scalar Field Theory. Schrodinger, Heisenberg and interaction representations. The Evolution operator and the S-matrix.
Propagators and path integrals. Propagator for a Relativistic Real and Complex Scalar Fields. Path-Integral representation of the S-matrix and Green's functions. Imaginary time. Minkowski space and Euclidean space

Non-Relativistic Field Theory ( pdf file ), updated: 10/23/2003

Review of Second Quantization for Many-Particle Systems. Many-Body Systems as a Field Theory. Non-Relativistic Fermions at zero temperature: ground state, spectrum of low-lying excitations.
Propagator for the Non-Relativistic Fermi Gas. Holes, particles and the analytic properties of the propagator.

Quantization of the Dirac Theory ( pdf file ), updated: 10/31/2003

Quantization of the Dirac Theory: ground state, spectrum, quantum numbers of excitations, causality and spin-statistics theorem.
Propagator for the Dirac Field Theory.

Coherent State Path Integrals ( pdf file ), updated: 12/9/2003

Coherent State path integral quantization of bosonic and fermionic systems.
Path integrals for spin.
Grassmann variables. Path integral quantization of the Dirac theory.
Fermion and Boson determinants. Zeta function regularization.

Quantization of Gauge Theories ( pdf file ), updated: 12/9/2003

Path-integral quantization of the Maxwell Abelian gauge theory; quantization and gauge fixing. Propagator for the free electromagnetic field. The Wilson loop operator. Path Integral quantization of Yang-Mills non-Abelian Gauge theories. Gauge fixing, covariant gauges and the Faddeev-Popov construction. Ghosts. BRST invariance.

Physical Observables and Propagators . ( pdf file ), updated: 12/10/2003

The Propagator in Non-Relativistic Quantum Mechanics: retarded, advanced and Feynman propagators. Green's Functions in Classical Electrodynamics.
Propagators, Time-Ordered Products and Green's Functions in Quantum Field Theory. S-matrix elements and Green's functions. Analytic properties. Lehman representation. Spectrum. Cross-sections and and the S-matrix.
Linear Response Theory. Measurements and correlation functions. Application to the electromagnetic response of a metal. Sum rules.

Perturbation Theory and Feynman Rules ( pdf file ), updated: 11/13/2003

Wick's Theorem, generating functional and perturbation theory. Perturbation expansion for vacuum amplitudes and Green's functions. Feynman Diagrams.
Feynman Rules for scalar fields and QED.
Feynman Rules for a non-relativistic Fermi-Gas at zero temperature.
Feynman Rules for the Landau Theory of Phase transitions.

Applications of Perturbation Theory

electron-positron anihilation and scattering processes in QED.
Hartree Approximation in many-body systems.
Mean Field Theory in Classical Statistical Mechanics.

Connected and Disconnected Green's functions.

Exponentiation of connected diagrams. Reducible and Irreducible Diagrams.
One particle Irreducible (1 PI) Vertex Functions. Physical content. Self Energy. Vacuum Polarization. Vertex Part.
The generating functional of 1PI vertex functions. Theory of the effective potential. Spontaneous and explicit symmetry breaking. Ward Identities.

Fluctuations and Radiative Corrections.

One-loop radiative corrections in QED. Gauge Invariance.
Divergencies, regularization and renormalization. Effective charge.
Fluctuations in the Landau Theory of phase transitions; mass and coupling constant renormalization (to 1 loop).
Hartree, Hartree-Fock and Random Phase Approximations in the Fermi gas: self energy, vacuum polarization, and vertex part. Dialectric Constant and Screening.

Canonical Transformations in Field Theory.

Bogoliubov Transformations for Fermi and Bose Systems. Ground state instabilities. Examples, BCS superconductors (baby version).
Jordan-Wigner transformation and quantum spin chains. Diagonalization and spectra.

Finite Temperature Field Theory and Quantum Statistical mechanics

Fermions and Bosons. Boundary Conditions. Matsubara sums. Thermal Green's function. Feynman rules. Response functions at finite temperature and frequency.

Path Integrals: connection between Classical Statistical Mechanics and Quantum Field Theory

Path Integrals and the connection between Classical Statistical Mechanics and Quantum Field Theory. The Transfer Matrix. The Ising Model as a Quantum Field Theory.

Bibliography


Last updated 12/15/2003