Author: G. L. Sewell
Publisher: Oxford University Press, USA
ISBN:
Category : Language Arts & Disciplines
Languages : en
Pages : 260
Book Description
This study provides a systematic approach to the quantum theory of collective phenomena, based principally on the model of infinite systems. The author sets the theory within the framework of modern statistical mechanics, formulating it in rigorous, though relatively simple, mathematical terms. This approach leads to a generalized form of statistical thermodynamics, and to useful characterizations of such collective phenomena as phase transitions, irreversibility, and metastability, going beyond the scope of traditional statistical mechanics of finite systems.
Quantum Theory of Collective Phenomena
Author: G. L. Sewell
Publisher: Oxford University Press, USA
ISBN:
Category : Language Arts & Disciplines
Languages : en
Pages : 260
Book Description
This study provides a systematic approach to the quantum theory of collective phenomena, based principally on the model of infinite systems. The author sets the theory within the framework of modern statistical mechanics, formulating it in rigorous, though relatively simple, mathematical terms. This approach leads to a generalized form of statistical thermodynamics, and to useful characterizations of such collective phenomena as phase transitions, irreversibility, and metastability, going beyond the scope of traditional statistical mechanics of finite systems.
Publisher: Oxford University Press, USA
ISBN:
Category : Language Arts & Disciplines
Languages : en
Pages : 260
Book Description
This study provides a systematic approach to the quantum theory of collective phenomena, based principally on the model of infinite systems. The author sets the theory within the framework of modern statistical mechanics, formulating it in rigorous, though relatively simple, mathematical terms. This approach leads to a generalized form of statistical thermodynamics, and to useful characterizations of such collective phenomena as phase transitions, irreversibility, and metastability, going beyond the scope of traditional statistical mechanics of finite systems.
Quantum Theory of Collective Phenomena
Author: G. L. Sewell
Publisher: Courier Corporation
ISBN: 0486780449
Category : Science
Languages : en
Pages : 260
Book Description
This systematic approach to the quantum theory of collective phenomena is based principally on the model of infinite systems. Suitable for advanced undergraduates and graduate students of physics and chemistry, the three-part treatment begins with an exposition of the generalized form of quantum theory of both finite and infinite systems. Part II consists of a general formulation of statistical thermodynamics, and the final part provides a treatment of the phenomena of phase transitions, metastability, and the generation of ordered structures far from equilibrium. "An excellent and competent introduction to the field … [and] … a source of information for the expert."—Physics Today "This a book of major importance…. I trust that this book will be used as a basis for the teaching of a balanced, modern and rigorous course on statistical mechanics in all universities."—Bulletin of the London Mathematical Society "This is one of the best introductions to the subject, and it is strongly recommended to anyone interested in collective phenomena."—Physics Bulletin "The book may be recommended for students as a well-balanced introduction to this rich subject and it can serve as a useful handbook for the expert."—Journal of Statistical Physics
Publisher: Courier Corporation
ISBN: 0486780449
Category : Science
Languages : en
Pages : 260
Book Description
This systematic approach to the quantum theory of collective phenomena is based principally on the model of infinite systems. Suitable for advanced undergraduates and graduate students of physics and chemistry, the three-part treatment begins with an exposition of the generalized form of quantum theory of both finite and infinite systems. Part II consists of a general formulation of statistical thermodynamics, and the final part provides a treatment of the phenomena of phase transitions, metastability, and the generation of ordered structures far from equilibrium. "An excellent and competent introduction to the field … [and] … a source of information for the expert."—Physics Today "This a book of major importance…. I trust that this book will be used as a basis for the teaching of a balanced, modern and rigorous course on statistical mechanics in all universities."—Bulletin of the London Mathematical Society "This is one of the best introductions to the subject, and it is strongly recommended to anyone interested in collective phenomena."—Physics Bulletin "The book may be recommended for students as a well-balanced introduction to this rich subject and it can serve as a useful handbook for the expert."—Journal of Statistical Physics
Quantum Theory and Its Stochastic Limit
Author: Luigi Accardi
Publisher: Springer Science & Business Media
ISBN: 3662049295
Category : Science
Languages : en
Pages : 485
Book Description
Well suited as a textbook in the emerging field of stochastic limit, which is a new mathematical technique developed for solving nonlinear problems in quantum theory.
Publisher: Springer Science & Business Media
ISBN: 3662049295
Category : Science
Languages : en
Pages : 485
Book Description
Well suited as a textbook in the emerging field of stochastic limit, which is a new mathematical technique developed for solving nonlinear problems in quantum theory.
Non-linear And Collective Phenomena In Quantum Physics: A Reprint Volume From Physics Reports
Author: Maurice Jacob
Publisher: World Scientific
ISBN: 9814518891
Category : Science
Languages : en
Pages : 526
Book Description
Contents: Extended Systems in Field Theory :Introduction (J-L Gervais and A Neveu)Vortices and Quark Confinement in Non-Abelian Gauge Theories (S Mandelstam)Magnetic and Electric Confinement of Quarks (Y Nambu)Examples of Four-Dimensional Soliton Solutions and Abnormal Nuclear States (T D Lee)Classical Solution in the Massive Thirring Model (S-J Chang)Semiclassical Quantization Methods in Field Theory (A Neveu)The Quantum Theory of Solitons and Other Non-Linear Classical Waves (R Jackiw)Collective Coordinate Method for Quantization of Extended Systems (J-L Gervais, A Jevicki and B Sakita)Quantum Expansion of Soliton Solutions (N H Christ)Hartree-Type Approximation Applied to a ϕ4 Field Theory (S-J Chang)Soliton Operators for the Quantized Sine–Gordon Equation (S Mandelstam)Classical Aspects and Fluctuation-Behaviour of Two Dimensional Models in Statistical Mechanics and Many Body Physics (B Schroer)Quarks on a Lattice, or, the Colored String Model (K G Wilson)New Ideas about Confinement (L Susskind and J Kogut)Gauge Fields on a Lattice (C Itzykson)Non-Perturbative Aspects in Quantum Field Theory:Self-Dual Solutions to Euclidean Yang–Mills Equations (E Corrigan)An Introduction to the Twistor Programme (J Madore, J L Richard and R Stora)Collective Coordinates with Non-Trivial Dynamics (J-L Gervais)A Theory of the Strong Interactions (D J Gross)Magneticmonopoles (D Olive)Dynamical and Topological Considerations on Quark Confinement (F Englert and P Windey)Difficulties in Fixing the Gauge in Non-Abelian Gauge Theories (S Sciuto)Indeterminate-Mass Particles (B M Mccoy and T T Wu)Duality for Discrete Lattice Gauge Fields (C Itzykson)Large Order Estimates in Perturbation Theory (J Zinn-Justin)The Borel Transform and the Renormalization Group (G Parisi)Planar Diagrams (E Brezin)Exact S-Matrices and Form Factors in 1 + 1 Dimensional Field Theoretic Models with Soliton Behaviour (M Karowski)Topology and Higher Symmetries of the Two-Dimensional Nonlinear σ Model (A D'adda, M Luscher and P Di Vecchia)Two-Dimensional Yang–Mills Theory in the Leading 1/N Expansion (T T Wu)Superfluidity and the Two-Dimensional XY Model' (D R Nelson)Bosonized Fermions in Three Dimensions (A Luther)Symmetry and Topology Concepts for Spin Glasses and Other Glasses (G Toulouse)Common Trends in Particle and Condensed Matter Physics:Introduction to Localization(D J Thouless)Conductivity Scaling and Localization(E Abrahams)Disordered Electronic System as a Model of Interacting Matrices(F Wegner)Status Report on Spin Glasses (Not Included in this Report)(S Kirkpatrick)Mean Field Theory for Spin Glasses(G Parisi)The Random Energy Model(B Derrida)Towards a Mean Field Theory of Spin Glasses: the Tap Route Revisited (C De Dominicis)On the Connection Between Spin Glasses and Gauge Field Theories(G Toulouse, J Vannimenus)Monte Carlo Simulations of Lattice Gauge Theories(C Rebbi)Large Dimension Expansions and Transition Patterns in Lattice Gauge Theories(J-M Drouffe)Progress in Lattice Gauge Theory(J B Kogut)Phase Structure of the Z(2) Gauge and Matter Theory(D Horn)General Introduction to Confinement(S Mandelstam)A Simple Picture of the Weak-to-Strong Coupling Transition in Quantum Chromodynamics(C G Callan Jr.)Quantum Fluctuations in a Multiinstanton Background(B A Berg)Some Comments on the Crossover Between Strong and Weak Coupling in Su(2) Pure Yang–Mills Theory(J Frohlich)String Dynamics in QCD (J-L Gervais, A Neveu)Dual Models and Strings: The Critical Dimension(C B Thorn: )Duality and Finite Size Effects in Six Vertex Models(C.B. Thorn: )Scaling at a Bifurcation Point(M Nauenberg, D Scalapino)Some Implications of a Cosmological Phase Transition(T W B Kibble) Readership: Graduate students and researchers in particle physics andcondensed matter physics.
Publisher: World Scientific
ISBN: 9814518891
Category : Science
Languages : en
Pages : 526
Book Description
Contents: Extended Systems in Field Theory :Introduction (J-L Gervais and A Neveu)Vortices and Quark Confinement in Non-Abelian Gauge Theories (S Mandelstam)Magnetic and Electric Confinement of Quarks (Y Nambu)Examples of Four-Dimensional Soliton Solutions and Abnormal Nuclear States (T D Lee)Classical Solution in the Massive Thirring Model (S-J Chang)Semiclassical Quantization Methods in Field Theory (A Neveu)The Quantum Theory of Solitons and Other Non-Linear Classical Waves (R Jackiw)Collective Coordinate Method for Quantization of Extended Systems (J-L Gervais, A Jevicki and B Sakita)Quantum Expansion of Soliton Solutions (N H Christ)Hartree-Type Approximation Applied to a ϕ4 Field Theory (S-J Chang)Soliton Operators for the Quantized Sine–Gordon Equation (S Mandelstam)Classical Aspects and Fluctuation-Behaviour of Two Dimensional Models in Statistical Mechanics and Many Body Physics (B Schroer)Quarks on a Lattice, or, the Colored String Model (K G Wilson)New Ideas about Confinement (L Susskind and J Kogut)Gauge Fields on a Lattice (C Itzykson)Non-Perturbative Aspects in Quantum Field Theory:Self-Dual Solutions to Euclidean Yang–Mills Equations (E Corrigan)An Introduction to the Twistor Programme (J Madore, J L Richard and R Stora)Collective Coordinates with Non-Trivial Dynamics (J-L Gervais)A Theory of the Strong Interactions (D J Gross)Magneticmonopoles (D Olive)Dynamical and Topological Considerations on Quark Confinement (F Englert and P Windey)Difficulties in Fixing the Gauge in Non-Abelian Gauge Theories (S Sciuto)Indeterminate-Mass Particles (B M Mccoy and T T Wu)Duality for Discrete Lattice Gauge Fields (C Itzykson)Large Order Estimates in Perturbation Theory (J Zinn-Justin)The Borel Transform and the Renormalization Group (G Parisi)Planar Diagrams (E Brezin)Exact S-Matrices and Form Factors in 1 + 1 Dimensional Field Theoretic Models with Soliton Behaviour (M Karowski)Topology and Higher Symmetries of the Two-Dimensional Nonlinear σ Model (A D'adda, M Luscher and P Di Vecchia)Two-Dimensional Yang–Mills Theory in the Leading 1/N Expansion (T T Wu)Superfluidity and the Two-Dimensional XY Model' (D R Nelson)Bosonized Fermions in Three Dimensions (A Luther)Symmetry and Topology Concepts for Spin Glasses and Other Glasses (G Toulouse)Common Trends in Particle and Condensed Matter Physics:Introduction to Localization(D J Thouless)Conductivity Scaling and Localization(E Abrahams)Disordered Electronic System as a Model of Interacting Matrices(F Wegner)Status Report on Spin Glasses (Not Included in this Report)(S Kirkpatrick)Mean Field Theory for Spin Glasses(G Parisi)The Random Energy Model(B Derrida)Towards a Mean Field Theory of Spin Glasses: the Tap Route Revisited (C De Dominicis)On the Connection Between Spin Glasses and Gauge Field Theories(G Toulouse, J Vannimenus)Monte Carlo Simulations of Lattice Gauge Theories(C Rebbi)Large Dimension Expansions and Transition Patterns in Lattice Gauge Theories(J-M Drouffe)Progress in Lattice Gauge Theory(J B Kogut)Phase Structure of the Z(2) Gauge and Matter Theory(D Horn)General Introduction to Confinement(S Mandelstam)A Simple Picture of the Weak-to-Strong Coupling Transition in Quantum Chromodynamics(C G Callan Jr.)Quantum Fluctuations in a Multiinstanton Background(B A Berg)Some Comments on the Crossover Between Strong and Weak Coupling in Su(2) Pure Yang–Mills Theory(J Frohlich)String Dynamics in QCD (J-L Gervais, A Neveu)Dual Models and Strings: The Critical Dimension(C B Thorn: )Duality and Finite Size Effects in Six Vertex Models(C.B. Thorn: )Scaling at a Bifurcation Point(M Nauenberg, D Scalapino)Some Implications of a Cosmological Phase Transition(T W B Kibble) Readership: Graduate students and researchers in particle physics andcondensed matter physics.
Condensed Matter Field Theory
Author: Alexander Altland
Publisher: Cambridge University Press
ISBN: 0521769752
Category : Science
Languages : en
Pages : 785
Book Description
This primer is aimed at elevating graduate students of condensed matter theory to a level where they can engage in independent research. Topics covered include second quantisation, path and functional field integration, mean-field theory and collective phenomena.
Publisher: Cambridge University Press
ISBN: 0521769752
Category : Science
Languages : en
Pages : 785
Book Description
This primer is aimed at elevating graduate students of condensed matter theory to a level where they can engage in independent research. Topics covered include second quantisation, path and functional field integration, mean-field theory and collective phenomena.
Collective Classical And Quantum Fields: In Plasmas, Superconductors, Superfluid 3he, And Liquid Crystals
Author: Hagen Kleinert
Publisher: World Scientific Publishing Company
ISBN: 9813223960
Category : Science
Languages : en
Pages : 423
Book Description
This is an introductory book dealing with collective phenomena in many-body systems. A gas of bosons or fermions can show oscillations of various types of density. These are described by different combinations of field variables. Especially delicate is the competition of these variables. In superfluid 3He, for example, the atoms can be attracted to each other by molecular forces, whereas they are repelled from each other at short distance due to a hardcore repulsion. The attraction gives rise to Cooper pairs, and the repulsion is overcome by paramagnon oscillations. The combination is what finally led to the discovery of superfluidity in 3He. In general, the competition between various channels can most efficiently be studied by means of a classical version of the Hubbard-Stratonovich transformation.A gas of electrons is controlled by the interplay of plasma oscillations and pair formation. In a system of rod- or disc-like molecules, liquid crystals are observed with directional orientations that behave in unusual five-fold or seven-fold symmetry patterns. The existence of such a symmetry was postulated in 1975 by the author and K Maki. An aluminium material of this type was later manufactured by Dan Shechtman which won him the 2014 Nobel prize. The last chapter presents some solvable models, one of which was the first to illustrate the existence of broken supersymmetry in nuclei.
Publisher: World Scientific Publishing Company
ISBN: 9813223960
Category : Science
Languages : en
Pages : 423
Book Description
This is an introductory book dealing with collective phenomena in many-body systems. A gas of bosons or fermions can show oscillations of various types of density. These are described by different combinations of field variables. Especially delicate is the competition of these variables. In superfluid 3He, for example, the atoms can be attracted to each other by molecular forces, whereas they are repelled from each other at short distance due to a hardcore repulsion. The attraction gives rise to Cooper pairs, and the repulsion is overcome by paramagnon oscillations. The combination is what finally led to the discovery of superfluidity in 3He. In general, the competition between various channels can most efficiently be studied by means of a classical version of the Hubbard-Stratonovich transformation.A gas of electrons is controlled by the interplay of plasma oscillations and pair formation. In a system of rod- or disc-like molecules, liquid crystals are observed with directional orientations that behave in unusual five-fold or seven-fold symmetry patterns. The existence of such a symmetry was postulated in 1975 by the author and K Maki. An aluminium material of this type was later manufactured by Dan Shechtman which won him the 2014 Nobel prize. The last chapter presents some solvable models, one of which was the first to illustrate the existence of broken supersymmetry in nuclei.
Non-linear and Collective Phenomena in Quantum Physics
Author: J. L. Gervais
Publisher: World Scientific
ISBN: 9789971950644
Category : Science
Languages : en
Pages : 532
Book Description
http://www.worldscientific.com/worldscibooks/10.1142/0040
Publisher: World Scientific
ISBN: 9789971950644
Category : Science
Languages : en
Pages : 532
Book Description
http://www.worldscientific.com/worldscibooks/10.1142/0040
Collective Electrodynamics
Author: Carver A. Mead
Publisher: MIT Press
ISBN: 9780262632607
Category : Science
Languages : en
Pages : 162
Book Description
In this book Carver Mead offers a radically new approach to the standard problems of electromagnetic theory. Motivated by the belief that the goal of scientific research should be the simplification and unification of knowledge, he describes a new way of doing electrodynamics—collective electrodynamics—that does not rely on Maxwell's equations, but rather uses the quantum nature of matter as its sole basis. Collective electrodynamics is a way of looking at how electrons interact, based on experiments that tell us about the electrons directly. (As Mead points out, Maxwell had no access to these experiments.) The results Mead derives for standard electromagnetic problems are identical to those found in any text. Collective electrodynamics reveals, however, that quantities that we usually think of as being very different are, in fact, the same—that electromagnetic phenomena are simple and direct manifestations of quantum phenomena. Mead views his approach as a first step toward reformulating quantum concepts in a clear and comprehensible manner. The book is divided into five sections: magnetic interaction of steady currents, propagating waves, electromagnetic energy, radiation in free space, and electromagnetic interaction of atoms. In an engaging preface, Mead tells how his approach to electromagnetic theory was inspired by his interaction with Richard Feynman.
Publisher: MIT Press
ISBN: 9780262632607
Category : Science
Languages : en
Pages : 162
Book Description
In this book Carver Mead offers a radically new approach to the standard problems of electromagnetic theory. Motivated by the belief that the goal of scientific research should be the simplification and unification of knowledge, he describes a new way of doing electrodynamics—collective electrodynamics—that does not rely on Maxwell's equations, but rather uses the quantum nature of matter as its sole basis. Collective electrodynamics is a way of looking at how electrons interact, based on experiments that tell us about the electrons directly. (As Mead points out, Maxwell had no access to these experiments.) The results Mead derives for standard electromagnetic problems are identical to those found in any text. Collective electrodynamics reveals, however, that quantities that we usually think of as being very different are, in fact, the same—that electromagnetic phenomena are simple and direct manifestations of quantum phenomena. Mead views his approach as a first step toward reformulating quantum concepts in a clear and comprehensible manner. The book is divided into five sections: magnetic interaction of steady currents, propagating waves, electromagnetic energy, radiation in free space, and electromagnetic interaction of atoms. In an engaging preface, Mead tells how his approach to electromagnetic theory was inspired by his interaction with Richard Feynman.
Quantum Field Theory in a Nutshell
Author: Anthony Zee
Publisher: Princeton University Press
ISBN: 1400835321
Category : Science
Languages : en
Pages : 605
Book Description
A fully updated edition of the classic text by acclaimed physicist A. Zee Since it was first published, Quantum Field Theory in a Nutshell has quickly established itself as the most accessible and comprehensive introduction to this profound and deeply fascinating area of theoretical physics. Now in this fully revised and expanded edition, A. Zee covers the latest advances while providing a solid conceptual foundation for students to build on, making this the most up-to-date and modern textbook on quantum field theory available. This expanded edition features several additional chapters, as well as an entirely new section describing recent developments in quantum field theory such as gravitational waves, the helicity spinor formalism, on-shell gluon scattering, recursion relations for amplitudes with complex momenta, and the hidden connection between Yang-Mills theory and Einstein gravity. Zee also provides added exercises, explanations, and examples, as well as detailed appendices, solutions to selected exercises, and suggestions for further reading. The most accessible and comprehensive introductory textbook available Features a fully revised, updated, and expanded text Covers the latest exciting advances in the field Includes new exercises Offers a one-of-a-kind resource for students and researchers Leading universities that have adopted this book include: Arizona State University Boston University Brandeis University Brown University California Institute of Technology Carnegie Mellon College of William & Mary Cornell Harvard University Massachusetts Institute of Technology Northwestern University Ohio State University Princeton University Purdue University - Main Campus Rensselaer Polytechnic Institute Rutgers University - New Brunswick Stanford University University of California - Berkeley University of Central Florida University of Chicago University of Michigan University of Montreal University of Notre Dame Vanderbilt University Virginia Tech University
Publisher: Princeton University Press
ISBN: 1400835321
Category : Science
Languages : en
Pages : 605
Book Description
A fully updated edition of the classic text by acclaimed physicist A. Zee Since it was first published, Quantum Field Theory in a Nutshell has quickly established itself as the most accessible and comprehensive introduction to this profound and deeply fascinating area of theoretical physics. Now in this fully revised and expanded edition, A. Zee covers the latest advances while providing a solid conceptual foundation for students to build on, making this the most up-to-date and modern textbook on quantum field theory available. This expanded edition features several additional chapters, as well as an entirely new section describing recent developments in quantum field theory such as gravitational waves, the helicity spinor formalism, on-shell gluon scattering, recursion relations for amplitudes with complex momenta, and the hidden connection between Yang-Mills theory and Einstein gravity. Zee also provides added exercises, explanations, and examples, as well as detailed appendices, solutions to selected exercises, and suggestions for further reading. The most accessible and comprehensive introductory textbook available Features a fully revised, updated, and expanded text Covers the latest exciting advances in the field Includes new exercises Offers a one-of-a-kind resource for students and researchers Leading universities that have adopted this book include: Arizona State University Boston University Brandeis University Brown University California Institute of Technology Carnegie Mellon College of William & Mary Cornell Harvard University Massachusetts Institute of Technology Northwestern University Ohio State University Princeton University Purdue University - Main Campus Rensselaer Polytechnic Institute Rutgers University - New Brunswick Stanford University University of California - Berkeley University of Central Florida University of Chicago University of Michigan University of Montreal University of Notre Dame Vanderbilt University Virginia Tech University
Quantum Theory of Finite Systems
Author: Jean-Paul Blaizot
Publisher: Mit Press
ISBN: 9780262022149
Category : Science
Languages : en
Pages : 657
Book Description
This book provides a comprehensive and pedagogical account of the various methods used in the quantum theory of finite systems, including molecular, atomic, nuclear, and particle phenomena. Covering both background material and advanced topics and including nearly 200 problems, Quantum Theory of Finite Systems has been designed to serve primarily as a text and will also prove useful as a reference in research. The first of the book's four parts introduces the basic mathematical apparatus: second quantization, canonical transformations, Wick theorems and the resulting diagram expansions, and oscillator models. The second part presents mean field approximations and the recently developed path integral methods for the quantization of collective modes. Part three develops perturbation theory in terms of both time-dependent Feynman diagrams and time-independent Goldstone diagrams. A fourth part discusses variational methods based on correlated wavefunctions, including spin correlations. The approximation schemes are formulated for fermions and bosons at eigher zero or non-zero temperature. Although the formalism developed applies to both finite and infinite systems, the book stresses those aspects of the theory that are specific to the description of finite systems. Thus special attention is given to mean field approximations, the ensuing broken symmetries, and the associated collective motions such as rotations. Conversely, some specific features of systems with infinite numbers of degrees of freedom (such as the thermodynamic limit, critical phenomena, and the elimination of ultraviolet divergencies) are deliberately omitted. Jean-Paul Blaizot and Georges Ripka are associated with the Centre d'Etudes Nucleaires de Saclay.
Publisher: Mit Press
ISBN: 9780262022149
Category : Science
Languages : en
Pages : 657
Book Description
This book provides a comprehensive and pedagogical account of the various methods used in the quantum theory of finite systems, including molecular, atomic, nuclear, and particle phenomena. Covering both background material and advanced topics and including nearly 200 problems, Quantum Theory of Finite Systems has been designed to serve primarily as a text and will also prove useful as a reference in research. The first of the book's four parts introduces the basic mathematical apparatus: second quantization, canonical transformations, Wick theorems and the resulting diagram expansions, and oscillator models. The second part presents mean field approximations and the recently developed path integral methods for the quantization of collective modes. Part three develops perturbation theory in terms of both time-dependent Feynman diagrams and time-independent Goldstone diagrams. A fourth part discusses variational methods based on correlated wavefunctions, including spin correlations. The approximation schemes are formulated for fermions and bosons at eigher zero or non-zero temperature. Although the formalism developed applies to both finite and infinite systems, the book stresses those aspects of the theory that are specific to the description of finite systems. Thus special attention is given to mean field approximations, the ensuing broken symmetries, and the associated collective motions such as rotations. Conversely, some specific features of systems with infinite numbers of degrees of freedom (such as the thermodynamic limit, critical phenomena, and the elimination of ultraviolet divergencies) are deliberately omitted. Jean-Paul Blaizot and Georges Ripka are associated with the Centre d'Etudes Nucleaires de Saclay.