Ludwig / Falter Symmetries in Physics

Group Theory Applied to Physical Problems
1988
ISBN: 978-3-642-97029-0
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, Band 64, 461 Seiten, eBook

Reihe: Springer Series in Solid-State Sciences

Everyone knows that symmetry is fundamentally important in physics. On one hand, the symmetry of a system is often the starting point for general physical considerations, and on the other hand, particular problems may be solved in simpler and more elegant ways if symmetry is taken into account. This book presents the underlying theories of symmetry and gives examples of their application in branches of physics ranging from solid-state to high-energy physics via atomic and molecular physics. The text is as self-contained as possible, with as much mathematical formalism given as required. The main emphasis is on the theory of group representations and on the method of projection operators, this is a very powerful tool which is often treated only very briefly. Discrete symmetries, continuous symmetries and symmetry breaking are also discussed, and exercises are provided to stimulate the reader to carry out original work.

Zielgruppe

Research

Autoren/Hrsg.

Ludwig, Wolfgang

Falter, Claus

Inhaltsverzeichnis

1. Introduction.- 2. Elements of the Theory of Finite Groups.- 2.1 Symmetry and Group Concepts: A Basic Example.- 2.2 General Theorems on Group Theory.- 2.3 Conjugacy Classes.- 3. Discrete Symmetry Groups.- 3.1 Point Groups.- 3.2 Colour Groups and Magnetic Groups.- 3.3 Double Groups.- 3.4 Lattices, the Translation Group and Space Group.- 3.5 Permutation Groups.- 3.6 Other Finite Groups.- 4. Representations of Finite Groups.- 4.1 Linear Spaces and Operators.- 4.2 Introduction to the Theory of Representations.- 4.3 Group Algebra.- 4.4 Direct Products.- 5. Irreducible Representations of Special Groups.- 5.1 Point and Double Point Groups.- 5.2 Magnetic Point Groups. Time Reversal.- 5.3 Translation Groups.- 5.4 Permutation Groups.- 5.5 Tensor Representations.- 6. Tensor Operators and Expectation Values.- 6.1 Tensors and Spinors.- 6.2 The Wigner-Eckart Theorem.- 6.3 Eigenvalue Problems.- 6.4 Perturbation Calculus.- 7. Molecular Spectra.- 7.1 Molecular Vibrations.- 7.2 Electron Functions and Spectra.- 7.3 Manv-Electron Problems.- 8. Selection Rules and Matrix Elements.- 8.1 Selection Rules of Tensor Operators.- 8.2 The Jahn-Teller Theorem.- 8.3 Radiative Transitions.- 8.4 Crystal Field Theory.- 8.5 Independent Components of Material Tensors.- 9. Representations of Space Groups.- 9.1 Representations of Normal Space Groups.- 9.2 Allowable Irreducible Representations of the Little Group Gk.- 9.3 Projection Operators and Basis Functions.- 9.4 Representations of Magnetic Space Groups.- 10. Excitation Spectra and Selection Rules in Crystals.- 10.1 Spectra — Some General Statements.- 10.2 Lattice Vibrations.- 10.3 Electron Energy Bands.- 10.4 Selection Rules for Interactions in Crystals.- 11. Lie Groups and Lie Algebras.- 11.1 General Foundations.- 11.2 Unitary Representations ofLie Groups.- 11.3 Clebsch-Gordan Coefficients and the Wigner-Eckart Theorem.- 11.4 The Cartan-Weyl Basis for Semisimple Lie Algebras.- 12. Representations by Young Diagrams. The Method of Irreducible Tensors.- 13. Applications of the Theory of Continuous Groups.- 13.1 Elementary Particle Spectra.- 13.2 Atomic Spectra.- 13.3 Nuclear Spectra.- 13.4 Dynamical Symmetries of Classical Systems.- 14. Internal Symmetries and Gauge Theories.- 14.1 Internal Symmetries of Fields.- 14.2 Gauge Transformations of the First Kind.- 14.3 Gauge Transformations of the Second Kind.- 14.4 Gauge Theories with Spontaneously Broken Symmetry.- 14.5 Non-Abelian Gauge Theories and Symmetry Breaking.- Appendices.- References.- Additional References.