This monograph presents recent developments in quantum field theory at finite temperature. By using Lie groups, ideas from thermal theory are considered with concepts of symmetry, allowing for applications not only to quantum field theory but also to transport theory, quantum optics and statistical mechanics. This includes an analysis of geometrical and topological aspects of spatially confined systems with applications to the Casimir effect, superconductivity and phase transitions. Finally, some developments in open systems are also considered. The book provides a unified picture of the fundamental aspects in thermal quantum field theory and their applications, and is important to the field as a result, since it combines several diverse ideas that lead to a better understanding of different areas of physics.

Introduction to the relativistic thermal field theory and its applications in particle physics and astrophysics.

This book presents thermal field theory techniques, which can be applied in both cosmology and the theoretical description of the QCD plasma generated in heavy-ion collision experiments. It focuses on gauge interactions (whether weak or strong), which are essential in both contexts. As well as the many differences in the physics questions posed and in the microscopic forces playing a central role, the authors also explain the similarities and the techniques, such as the resummations, that are needed for developing a formally consistent perturbative expansion. The formalism is developed step by step, starting from quantum mechanics; introducing scalar, fermionic and gauge fields; describing the issues of infrared divergences; resummations and effective field theories; and incorporating systems with finite chemical potentials. With this machinery in place, the important class of real-time (dynamic) observables is treated in some detail. This is followed by an overview of a number of applications, ranging from the study of phase transitions and particle production rate computations, to the concept of transport and damping coefficients that play a ubiquitous role in current developments. The book serves as a self-contained textbook on relativistic thermal field theory for undergraduate and graduate students of theoretical high-energy physics.

This book focus on examining the thermodynamic properties of various prominent field theories concerning high-energy and condensed matter physics. We make the usage of the theory of ensembles to perform our analysis. At the beginning, we supply the thermodynamic properties based on the formalism of canonical ensemble to the Aharonov-Bohm quantum ring considering both scenarios: the relativistic and the non-relativistic cases. Next, we construct a model in order to study quantum gases. In this context, we examine bosons, fermions and spinless particles within the grand-canonical ensemble taking into account two different approaches: interacting and noninteracting particles. To corroborate our results, we apply them to the Bose-Einstein condensate and to the helium dimmers. The same approach is applied considering rather Lorentz violation. Moreover, in this context, we also propose two applications to support our theoretical calculations: phosphorene layers and spin precession of quantum gases. Next, the thermodynamic properties are investigated as well to a variety of models/theories (regarding different energy dispersion relations) when the Lorentz symmetry is no longer maintained within the canonical ensemble formalism. To these cases, three distinct thermal scenarios of the universe are considered: the cosmic microwave background, the electroweak epoch, and the inflationary period.

"Thermal field theory is the study of quantum field theory at non-zero temperature. This proceedings introduces both retrospect and prospect for various aspects of thermal field theory as well as their extensive applications to condensed matter physics, high energy physics, cosmology, nuclear physics, etc. Also included are speeches memorizing the recently lamented Professor Hiroomi Umezawa, a leading physicist in thermal field theory, by his former students and colleagues."--Publisher's website.

This book discusses all three formalisms used in the study of finite temperature field theory, namely the imaginary time formalism, the closed time formalism and thermofield dynamics. In addition, the finite temperature description on an arbitrary path in the complex t-plane is also described in detail. Gauge field theories and symmetry restoration at finite temperature are among the practical examples discussed in depth. The thermal operator representation relating the zero temperature Feynman graphs to the finite temperature ones are also explained in depth. Applications of the formalisms are worked out in detail. The consistent generalization of light-front field theories to finite temperature is systematically explained as well as the phenomenon of Unruh radiation. Cutting (Cutcosky) rules for the imaginary parts of amplitudes at finite temperature are discussed in careful detail and examples are worked out. Spontaneous and dynamical symmetry breaking and possible symmetry restoration at finite temperature are described. The question of gauge dependence of the effective potential as well as physical parameters (like mass) and the Nielsen identities are explained with examples. The methods for calculating effective actions at finite temperature are described with examples. The subtleties which arise at finite temperature are pointed out in detail also with examples. The nonrestoration of some of the symmetries at high temperature (such as supersymmetry) and theories on nonsimply connected space-times are described thoroughly. Examples of nonequilibrium phenomena are discussed with the disoriented chiral condensates as an illustration. Fluctuation-dissipation theorem is explained in detail and is worked out systematically for glassy materials. Several appendices are added at the end of some of the chapters to help the readers appreciate the discussions of the individual chapters.This book is a very useful tool for graduate students, teachers and researchers in theoretical physics.

Presenting the physics of the most challenging problems in condensed matter using the conceptual framework of quantum field theory, this book is of great interest to physicists in condensed matter and high energy and string theorists, as well as mathematicians. Revised and updated, this second edition features new chapters on the renormalization group, the Luttinger liquid, gauge theory, topological fluids, topological insulators and quantum entanglement. The book begins with the basic concepts and tools, developing them gradually to bring readers to the issues currently faced at the frontiers of research, such as topological phases of matter, quantum and classical critical phenomena, quantum Hall effects and superconductors. Other topics covered include one-dimensional strongly correlated systems, quantum ordered and disordered phases, topological structures in condensed matter and in field theory and fractional statistics.

This advanced, accessible textbook on effective field theories uses worked examples to bring this important topic to a wider audience.

This work begins by distinguishing the difference between quantum mechanics and quantum field theory. It then attempts to extend field theory by adding a thermal degree of freedom to phenomena occurring within a vacuum. The resulting quantum field theory is called Thermo Field Dynamics (TFD).