Top researchers in the field of gravitation present the state-of-the-art topics outlined in this book, ranging from the stability of rotating wormholes solutions supported by ghost scalar fields, modified gravity applied to wormholes, the study of novel semi-classical and nonlinear energy conditions, to the applications of quantum effects and the superluminal version of the warp drive in modified spacetime. Based on Einstein's field equations, this cutting-edge research area explores the more far-fetched theoretical outcomes of General Relativity and relates them to quantum field theory. This includes quantum energy inequalities, flux energy conditions, and wormhole curvature, and sheds light on not just the theoretical physics but also on the possible applications to warp drives and time travel. This book extensively explores the physical properties and characteristics of these 'exotic spacetimes,' describing in detail the general relativistic geometries that generate closed timelike curves.

Presents the current understanding of the nature of time and space, and an approachable explanation of Einstein's theory of special relativity; then goes on to connect these to possible time travel along with the accompanying paradoxes involved.

The proceedings of MG16 give a broad view of all aspects of gravitational physics and astrophysics, from mathematical issues to recent observations and experiments. The scientific program of the meeting included 46 plenary presentations, 3 public lectures, 5 round tables and 81 parallel sessions arranged during the intense six-day online meeting. All talks were recorded and are available on the ICRANet YouTube channel at the following link: www.icranet.org/video_mg16.These proceedings are a representative sample of the very many contributions made at the meeting. They contain 383 papers, among which 14 come from the plenary sessions.The material represented in these proceedings cover the following topics: accretion, active galactic nuclei, alternative theories of gravity, black holes (theory, observations and experiments), binaries, boson stars, cosmic microwave background, cosmic strings, dark energy and large scale structure, dark matter, education, exact solutions, early universe, fundamental interactions and stellar evolution, fast transients, gravitational waves, high energy physics, history of relativity, neutron stars, precision tests, quantum gravity, strong fields, and white dwarf; all of them represented by a large number of contributions.The online e-proceedings are published in an open access format.

Many physical properties of our universe, such as the relative strength of the fundamental interactions, the value of the cosmological constant, etc., appear to be fine-tuned for existence of human life. One possible explanation of this fine tuning assumes existence of a multiverse, which consists of a very large number of individual universes having different physical properties. Intelligent observers populate only a small subset of these universes, which are fine-tuned for life. In this book we will review several interesting metamaterial systems, which capture many features of important cosmological models and offer insights into the physics of many other non-trivial spacetime geometries, such as microscopic black holes, closed time-like curves (CTCs) and the Alcubierre warp drive.

Assuming basic knowledge of special and general relativity, this book guides the reader to problems under consideration in modern research, concerning black holes, wormholes, cosmology, and extra dimensions. Its first part is devoted to local strong field configurations (black holes and wormholes) in general relativity and its most relevant extensions: scalar-tensor, f(R), and multidimensional theories. The second part discusses cosmology, including inflation and problems of a unified description of the whole evolution of the universe. The third part concerns multidimensional theories of gravity and contains a number of original results obtained by the authors. Expository work is conducted for a mechanism of symmetries and fundamental constants formation. The original approach to nonlinear multidimensional gravity that is able to construct a unique perspective describing different phenomena is highlighted.Much of the content was previously presented only in journal publications and is new for book contents, e.g., on regular black holes, various scalar field solutions, wormholes and their stability, inflation, clusters of primordial black holes, and multidimensional gravity. The last two topics are added in this new edition of the book. The other chapters are also updated to include new discoveries like the detection of gravitational waves.

This volume presents the newest results and developments in the fast-moving field of astroparticle physics. The following topics are covered: dark matter, baryogenesis, neutrino physics and astrophysics, inflation, topological defects, cosmic ray physics and cosmological implications of grand unification, supersymmetry, superstrings and extra dimensions.

This book is based on lectures given at the first edition of the Domoschool, the International Alpine School in Mathematics and Physics, held in Domodossola, Italy, in July 2018. It is divided into two parts. Part I consists of four sets of lecture notes. These are extended versions of lectures given at the Domoschool, written by well-known experts in mathematics and physics related to General Relativity. Part II collects talks by selected participants, focusing on research related to General Relativity.

This book is for anyone who wants a fresh approach to modern physics. Are you tired of amusing anecdotes about scientists' personal lives and eureka moments? Bored of chronological narratives of scientific progress through the ages? No longer wowed by ideas like string theory? Interested in first principles thinking and what it can do for you? This book is for you. This book is designed to take you step by step through the fundamental principles that underlie the physics of space, time, and matter. It is a how-to guide for building up our universe from first principles. By posing questions and answering them with illustrations and examples, the book shows how we can demonstrate what we know about the universe with simple concepts and thought experiments. With this book, you too can apply first principles to build up your own model of the universe and how it works, one you can take with you, and apply it to other areas of your life such as your job, business, even your relationships. There are no complicated mathematics in this book and I have minimized the amount of jargon. Thus, it is suitable anyone of any educational background from high school on. The book aims to be straightforward about how we get from simple ideas to complex physical theories. So, if you are interested in a new way of looking at the universe and are not afraid to unlearn some of what you have learned, take a look inside.

Divided into three parts, this volume focuses on a summary of how relativity theories were born. It also discusses the ramifications of general relativity, such as black holes, space-time singularities, gravitational waves, the large scale structure of the cosmos, and more. It includes summaries of radical changes in the notions of space and time.

Drawing on pivotal work by Einstein, Wheeler, Thorne, Hawking, and others, Matt Visser charts the development and current state of Lorentzian wormhole physics. Dr. Visser shows that by pushing established physical theories to their limits, it is possible to deduce the true physics of such exotica as wormholes and time travel. The physical framework he uses is derived from one of the major research frontiers of modern theoretical physics: quantum gravity the intersection of classical Einstein gravity and quantum field theory. About the Author Matt Visser is Research Assistant Professor at Washington University, St. Louis. He has lectured in the United States and abroad on topics including wormhole physics, time travel, and the chronology protection conjecture. He has conducted postdoctoral research at both the University of Southern California and at Los Alamos National Laboratory.