Following the fundamental insights from quantum mechanics and general relativity, geometry itself should have a quantum description; the search for a complete understanding of this description is what drives the field of quantum gravity. Group field theory is an ambitious framework in which theories of quantum geometry are formulated, incorporating successful ideas from the fields of matrix models, ten-sor models, spin foam models and loop quantum gravity, as well as from the broader areas of quantum field theory and mathematical physics. This special issue collects recent work in group field theory and these related approaches, as well as other neighbouring fields (e.g., cosmology, quantum information and quantum foundations, statistical physics) to the extent that these are directly relevant to quantum gravity research.

This book provides the reader with an overview of the different mathematical attempts to quantize gravity written by leading experts in this field. Also discussed are the possible experimental bounds on quantum gravity effects. The contributions have been strictly refereed and are written in an accessible style. The present volume emerged from the 2nd Blaubeuren Workshop "Mathematical and Physical Aspects of Quantum Gravity".

Absolute concepts of time and energy are integral to standard thermal physics, but background independent systems are devoid of them. This thesis explores the foundational question of generalising equilibrium statistical mechanics to background independent systems, and applies the resulting formulation to non-perturbative discrete quantum gravity. It offers a discussion of the rich interface of thermal physics and quantum gravity in this context, providing a broad contextualisation of such topics. This work details how standard tools from many-body physics can be generalised to discrete quantum gravity labelled with graph-based, or dual polyhedral, quanta that are common to various approaches like tensorial group field theory, loop quantum gravity, dynamical triangulations and lattice quantum gravity. It provides a systematic investigation, both conceptual and technical, of quantum gravitational Gibbs states, thermofield double vacuum states, and their application in condensate cosmology to probe questions of Big Bang singularity resolution and geometric inflation.

This volume presents the state of the art in the research on new possibilities for communication and computation based on quantum theory and nonlocality, as well as related directions and problems. It discusses challenging issues: decoherence and irreversibility; nonlocality and superluminosity; photonics; quantum information and communication; quantum computation.

This book is a printed edition of the Special Issue "100 Years of Chronogeometrodynamics: the Status of the Einstein's Theory of Gravitation in Its Centennial Year" that was published in Universe

The discovery by Green and Schwarz in 1984 that ten-dimensional superstring theory is anomaly-free and finite only if the Yang-Mills gauge group is SO(32) or E8 x E8 has made the phenomenological possibilities of superstrings evident. Ths has resulted in a sudden surge of interest in superstrings unification. Since this fast-developing field is new to almost all theoretical physicist, this collection of basic pre-1985 references should be very valuable. This two volumes contain over 1000 pages of reprints plus some introductory comments by J Schwarz.

The concept of multiple unperceived dimensions in the universe is one of the hottest topics in contemporary physics. It is essential to current attempts to explain gravity and the underlying structure of the universe. The Great Beyond begins with Einstein’s famous quarrel with Heisenberg and Bohr, whose theories of uncertainty threatened the order Einstein believed was essential to the universe, and it was his rejection of uncertainty that drove him to ponder the existence of a fifth dimension. Beginning with this famous disagreement and culminating with an explanation of the newest "brane" approach, author Paul Halpern shows how current debates about the nature of reality began as age-old controversies, and addresses how the possibility of higher dimensions has influenced culture over the past one hundred years.