CODE  61842 

ACADEMIC YEAR  2022/2023 
CREDITS 

SCIENTIFIC DISCIPLINARY SECTOR  FIS/02 
TEACHING LOCATION 

SEMESTER  1° Semester 
TEACHING MATERIALS  AULAWEB 
This course is the natural continuation of the course "Quantum Physics". The applications of interest of ordinaruy quantum mechanics require familiarity with specific techniques for the study of systems with many degrees of freedom. The main purpose of this course is poroviding the student with the basic ideas of these techniques and illustrating the relevant applications, both in a manybody, non relativistic context and in the context of the relativistic extension of quantum physics.
Providing the student with basis concepts in relativistic electrodynamics, and with quantum mechanics of manybody systems in the context of second quantization.
The central aim of this course is learning techniques for the application of quantum mechanics to systems of actual physical interest: nonrelativistic systems with many degrees of freedom, and relativistic systems.
Specifically, the student will be able to apply the formalism of second quantization to problems of interest. The idea of a canonical transformation will be introduced and developed, together with its main applications.
Finally, the basic ideas for the development of a covariant perturbation theory will be given.
Classical physics: Foundations of analytical mechanics, statistical physics and classic electrodynamics.
Nonrelativistic quantum mechanics: basic formalism, perturbation theory, scattering theory.
Special theory of relativity: foundations, fourvector formulation.
The course is organized in six hours of lecture per week. Lectures are given at the blackboard, with no use of slides. About 30 to 40% of the total time is devoted to applications of the conceptual ideas, through exercises and problems.
1. Review of nonrelativistic quantum mechanics
2. Systems of identical bosons
2.a The formalism of second quantization
2.b States and observables in second quantization
2.c Wick's theorem
2.d Density operator for mixed states
2.e Generalization of Wick's theorem to mixed states
3. Electromagnetic fields in empty space
3.a Normal modes
3.b Quantization in the radiation gauge
3.c Energy, momentum and spin of photons
3.d IGauge invariance and polarization
4. Relativistic fields
4.a Principle of least action and relativistic invariance
4.b Scalar field
4.c Symmetryconservation theorem
4.d Quantization of the free real scalar field
4.e Quantization of the free complex scalar field
4.f U(1) symmetry; antiparticles
4.g Action for the free electromagnetic field
4.h Causality in field theory
5. Canonical transformations for bosonic systems
5.a Definition and general properties
5.b Coherent states
5.c Bogolubov transformations
5.d Coherent states of photons
6. Systems of identical fermions
6.a Formalism of second quantization
6.b States and observables in second quantization
6.c Wick's theorem
6.d Density operator for mixed states
6.e Generalization of Wick's theorem to mixed states
7. Canonical transformations for fermionic systems
7.a Bogolubov transformations
7.b Electron and holes
8. Spinor fields
8.a Spinor representations of the Lorentz group
8.b Weyl spinors
8.c Lagrangian density for righthanded Weyl spinors
8.d Quantization, energy and momentum of single particle states
8.e Parity inversion and lefthanded spinors
8.f Dirac spinors
8.g Solutions of the free Dirac equation
9. Interactions
9.a Charged particles in an external electromagnetic field
9.b Gauge invariance in quantum mechanics
9.c Dirac equation in the presence of an external electromagnetic field
9.d Yukawa interaction
9.e Isotopic spin symmetry of strong interactions
9.f Interaction representation and induced interactions
10. Towards covariant perturbation theory
10.a Timedependent perturbation theory
10.b Review of scattering theory
10.c Cross sections and decay rates
10.d Examples in a scalar theory
10.e Feynman rules for the scalar theory
10.f Feynman rules for quantum electrodynamics
10.g An axample: the Compton crosssection
Landau, Lifsitz 2  Field theory
Landau, Lifsitz 3  Quantum mechanics
Landau, Lifsitz 4  Relativistic quantum theory
Gerry, Knight  Introductory Quantum Optics, Cambridge
Becchi, Ridolfi  An Introduction to relativistic processes and the standard model of electroweak interactions
Becchi  Appunti di fisica teorica (2018 version, reviewed by G. Ridolfi)
Maiani  Meccanica quantistica relativistica e introduzione alla teoria dei campi
Ridolfi  Notes on the Course of Theoretical Physics
Office hours: The reception time is free, by prior telephone or email appointment. Dipartimento di Fisica, via Dodecaneso 33, 16146 Genova piano 7, studio 709 telefono: 010 3536406 email: nicola.maggiore@ge.infn.it
Office hours: The students may contact the teacher at any time, for discussions, clarifications of the lectures, suggestions for the solution of problems. A preliminary contact via email is suggested.
GIOVANNI RIDOLFI (President)
CARLA BIGGIO
NICOLA MAGGIORE
NICODEMO MAGNOLI
SIMONE MARZANI
September 24, 2019
The examination has a written test and an interview, usually a few days after the written test.
In the written test, the student will be asked to solve two problems in three hours. Students are allowed to look at books or notes.
The interview, usually 20 to 30 minutes, starts with a discussion of the results of the written test.
The purpose of the written test is the assesment of the operational capabilities of the sudent. Two problems are usually proposed: one of them is about nonrelativistic applications of second quantization, while the seciond one is about relativistic quantum physics
During the interview, starting from a discussion of the written test, the student is asked to prove his understanding of the conceptual foundations at the basis of the study of manybody quantum systems.
Date  Time  Location  Type  Notes 
