This monograph integrates unitary symmetry and combinatorics, showing in great detail how the coupling of angular momenta in quantum mechanics is related to binary trees, trivalent trees, cubic graphs, MacMahon's master theorem, and other basic combinatorial concepts. A comprehensive theory of recoupling matrices for quantum angular momentum is developed. For the general unitary group, polynomial forms in many variables called matrix Schur functions have the remarkable property of giving all irreducible representations of the general unitary group and are the basic objects of study. The structure of these irreducible polynomials and the reduction of their Kronecker product is developed in detail, as is the theory of tensor operators.

This monograph is a synthesis of the theory of the pairwise coupling of the angular momenta of arbitrarily many independent systems to the total angular momentum in which the universal role of doubly stochastic matrices and their quantum-mechanical probabilistic interpretation is a major theme. A uniform viewpoint is presented based on the structure of binary trees. This includes a systematic method for the evaluation of all 3n-j coefficients and their relationship to cubic graphs. A number of topical subjects that emerge naturally are also developed, such as the algebra of permutation matrices, the properties of magic squares and an associated generalized Regge form, the Zeilberger counting formula for alternating sign matrices, and the Heisenberg ring problem, viewed as a composite system in which the total angular momentum is conserved.The readership is intended to be advanced graduate students and researchers interested in learning about the relationship between unitary symmetry and combinatorics and challenging unsolved problems. The many examples serve partially as exercises, but this monograph is not a textbook. It is hoped that the topics presented promote further and more rigorous developments that lead to a deeper understanding of the angular momentum properties of complex systems viewed as composite wholes.

Notation -- Quantum angular momentum -- Composite systems -- Graphs and adjacency diagrams -- Generating functions -- The D[lambda] polynomials: form -- Operator actions in Hilbert space -- The D[lambda] polynomials: structure -- The general linear and unitary groups -- Tensor operator theory -- Compendium A. Basic algebraic objects -- Compendium B. Combinatorial objects.

1. Composite quantum systems. 1.1. Introduction. 1.2. Angular momentum state vectors of a composite system. 1.3. Standard form of the Kronecker direct sum. 1.4. Recoupling matrices. 1.5. Preliminary results on doubly stochastic matrices and permutation matrices. 1.6. Relationship between doubly stochastic matrices and density matrices in angular momentum theory -- 2. Algebra of permutation matrices. 2.1. Introduction. 2.2. Basis sets of permutation matrices -- 3. Coordinates of A in basis [symbol]. 3.1. Notations. 3.2. The A-expansion rule in the basis [symbol]. 3.3. Dual matrices in the basis set [symbol](e, p). 3.4. The general dual matrices in the basis [symbol](e, p) -- 4. Further applications of permutation matrices. 4.1. Introduction. 4.2. An algebra of young operators. 4.3. Matrix Schur functions. 4.4. Real orthogonal irreducible representations of S[symbol]. 4.5. Left and right regular representations of finite groups -- 5. Doubly stochastic matrices in angular momentum theory. 5.1. Introduction. 5.2. Abstractions and interpretations. 5.3. Permutation matrices as doubly stochastic. 5.4 The doubly stochastic matrix for a single system with angular momentum J. 5.5. Doubly stochastic matrices for composite angular momentum systems. 5.6. Binary coupling of angular momenta. 5.7. State vectors : Uncoupled and coupled. 5.8. General binary tree couplings and doubly stochastic matrices -- 6. Magic squares. 6.1. Review. 6.2. Magic squares and addition of angular momenta. 6.3. Rational generating function of H[symbol](r) -- 7. Alternating sign matrices. 7.1. Introduction. 7.2. Standard Gelfand-Tsetlin patterns. 7.3. Strict Gelfand-Tsetlin patterns for [symbol] = (nn-1 ... 21). 7.4. Sign-reversal-shift invariant polynomials. 7.5. The requirement of zeros. 7.6. The incidence matrix formulation -- 8. The Heisenberg magnetic ring. 8.1. Introduction. 8.2. Matrix elements of H in the uncoupled and coupled bases. 8.3. Exact solution of the Heisenberg ring magnet for n = 2,3,4. 8.4. The Heisenberg Ring Hamiltonian : Even n. 8.5. The Heisenberg Ring Hamiltonian : Odd n. 8.6. Recount, synthesis, and critique. 8.7 Action of the cyclic group. 8.8. Concluding remarks

This volume continues the series of proceedings of summer schools on theoretical physics which aim at an adequate description of the structure of condensed matter in terms of sophisticated, advanced mathematical tools. This time, the main emphasis is put on the question of whether (and when) the energy bands in solids are continuous. Profs. L Michel, J Zak and others consider the origin, existence and continuity of band structure. Also, some previously discussed problems (magnetic symmetry, flux quantization, statistics, quasicrystals, the Bethe ansatz) are pursued further, and appropriate mathematical tools, rooted in “actions of groups on sets”, are developed.

This is the fourth in a series of proceedings of the Combinatorial and Additive Number Theory (CANT) conferences, based on talks from the 2019 and 2020 workshops at the City University of New York. The latter was held online due to the COVID-19 pandemic, and featured speakers from North and South America, Europe, and Asia. The 2020 Zoom conference was the largest CANT conference in terms of the number of both lectures and participants. These proceedings contain 25 peer-reviewed and edited papers on current topics in number theory. Held every year since 2003 at the CUNY Graduate Center, the workshop surveys state-of-the-art open problems in combinatorial and additive number theory and related parts of mathematics. Topics featured in this volume include sumsets, zero-sum sequences, minimal complements, analytic and prime number theory, Hausdorff dimension, combinatorial and discrete geometry, and Ramsey theory. This selection of articles will be of relevance to both researchers and graduate students interested in current progress in number theory.

This collection represents a unique undertaking in scientific publishing to honor Nick Metropolis, the last survivor of the World War II Manhattan Project in Los Alamos. In this volume, some of the leading scientists and humanists of our time have contributed essays related to their respective disciplines, exploring various aspects of future developments in science and society, philosophy, national security, nuclear power, pure and applied mathematics, physics and biology, particle physics, computing, and information science.

In this third volume of his modern introduction to quantum field theory, Eberhard Zeidler examines the mathematical and physical aspects of gauge theory as a principle tool for describing the four fundamental forces which act in the universe: gravitative, electromagnetic, weak interaction and strong interaction. Volume III concentrates on the classical aspects of gauge theory, describing the four fundamental forces by the curvature of appropriate fiber bundles. This must be supplemented by the crucial, but elusive quantization procedure. The book is arranged in four sections, devoted to realizing the universal principle force equals curvature: Part I: The Euclidean Manifold as a Paradigm Part II: Ariadne's Thread in Gauge Theory Part III: Einstein's Theory of Special Relativity Part IV: Ariadne's Thread in Cohomology For students of mathematics the book is designed to demonstrate that detailed knowledge of the physical background helps to reveal interesting interrelationships among diverse mathematical topics. Physics students will be exposed to a fairly advanced mathematics, beyond the level covered in the typical physics curriculum. Quantum Field Theory builds a bridge between mathematicians and physicists, based on challenging questions about the fundamental forces in the universe (macrocosmos), and in the world of elementary particles (microcosmos).

This book contains twenty-two papers presented at the International Conference in Combinatorics, held in Jerusalem in May 1993. The papers describe some of the latest developments in algebraic combinatorics, enumeration, graph and hypergraph theory, combinatorial geometry, and geometry of polytopes and arrangements. The papers are accessible to specialists as well as nonspecialists.

Comprises a comprehensive reference source that unifies the entire fields of atomic molecular and optical (AMO) physics, assembling the principal ideas, techniques and results of the field. 92 chapters written by about 120 authors present the principal ideas, techniques and results of the field, together with a guide to the primary research literature (carefully edited to ensure a uniform coverage and style, with extensive cross-references). Along with a summary of key ideas, techniques, and results, many chapters offer diagrams of apparatus, graphs, and tables of data. From atomic spectroscopy to applications in comets, one finds contributions from over 100 authors, all leaders in their respective disciplines. Substantially updated and expanded since the original 1996 edition, it now contains several entirely new chapters covering current areas of great research interest that barely existed in 1996, such as Bose-Einstein condensation, quantum information, and cosmological variations of the fundamental constants. A fully-searchable CD- ROM version of the contents accompanies the handbook.