The Geometry of Dynamical Triangulations

The Geometry of Dynamical Triangulations
Author: Jan Ambjorn
Publisher: Springer Science & Business Media
Total Pages: 207
Release: 2009-02-17
Genre: Science
ISBN: 3540694277

The express purpose of these lecture notes is to go through some aspects of the simplicial quantum gravity model known as the dynamical triangula tions approach. Emphasis has been on laying the foundations of the theory and on illustrating its subtle and often unexplored connections with many distinct mathematical fields ranging from global Riemannian geometry, to moduli theory, number theory, and topology. Our exposition will concentrate on these points so that graduate students may find in these notes a useful exposition of some of the rigorous results one can -establish in this field and hopefully a source of inspiration for new exciting problems. We try as far as currently possible to expose the interplay between the analytical aspects of dynamical triangulations and the results of Monte Carlo simulations. The techniques described here are rather novel and allow us to address points of current interest in the subject of simplicial quantum gravity while requiring very little in the way of fancy field-theoretical arguments. As a consequence, these notes contain mostly original and until now unpublished material, which will hopefully be of interest both to the expert practitioner and to graduate students entering the field. Among the topics addressed here in considerable detail are the following. (i) An analytical discussion of the geometry of dynamical triangulations in dimensions n == 3 and n == 4.

Exploring Causal Dynamical Triangulations

Exploring Causal Dynamical Triangulations
Author: Joshua Harris Cooperman
Publisher:
Total Pages:
Release: 2013
Genre:
ISBN: 9781303538025

Causal dynamical triangulations is a novel approach to lattice regularization of the gravitational path integral. After motivating the study of quantum theories of gravity in general and of causal dynamical triangulations in particular in chapter 1, I introduce the theoretical formalism of causal dynamical triangulations in the context of quantizing Einstein gravity in chapter 2. I then explore a series of five topics in causal dynamical triangulations in the five ensuing chapters. I begin in chapter 3 by considering the gravitational effective action that describes the ensemble average quantum spacetime geometry on sufficiently large scales of (the ground state of a certain phase of) the causal dynamical triangulations of Einstein gravity. This discussion sets the stage for much of the analysis contained in the next four chapters. In chapter 4 I make substantial use of this effective action in developing a method for extracting renormalization group flows of gravitational couplings. Next I present in chapter 5 the spectral dimension, an observable measuring the scale dependent dimensionality of a space that has notably elucidated the physical nature of quantum spacetime geometry emerging from causal dynamical triangulations. Within the causal dynamical triangulations of (2+1)-dimensional Einstein gravity, I study transition amplitudes between past and future spacelike boundaries of fixed intrinsic geometries in chapter 6. Employing the techniques of causal dynamical triangulations, I perform a quantization of (2+1)-dimensional projectable Horava-Lifshitz gravity in chapter 7. Finally, I discuss my ongoing research in and the theoretical prospects for causal dynamical triangulations in chapter 8.

M-Theory and Quantum Geometry

M-Theory and Quantum Geometry
Author: Lárus Thorlacius
Publisher: Springer Science & Business Media
Total Pages: 472
Release: 2012-12-06
Genre: Science
ISBN: 940114303X

The fundamental structure of matter and spacetime at the shortest length scales remains an exciting frontier of basic research in theoretical physics. A unifying theme in this area is the quantization of geometrical objects. The majority of lectures at the Advanced Study Institute on Quantum Ge ometry in Akureyri was on recent advances in superstring theory, which is the leading candidate for a unified description of all known elementary par ticles and interactions. The geometric concept of one-dimensional extended objects, or strings, has always been at the core of superstring theory but in recent years the focus has shifted to include also higher-dimensional ob jects, so called D-branes, which play a key role in the non-perturbative dynamics of the theory. A related development has seen the strong coupling regime of a given string theory identified with the weak coupling regime of what was previ ously believed to be a different theory, and a web of such" dualities" that interrelates all known superstring theories has emerged. The resulting uni fied theoretical framework, termed M-theory, has evolved at a rapid pace in recent years.

M-Theory and Quantum Geometry

M-Theory and Quantum Geometry
Author: Lárus Thorlacius
Publisher: Springer Science & Business Media
Total Pages: 476
Release: 2000-09-30
Genre: Mathematics
ISBN: 9780792364757

Papers from an August 1999 NATO Advanced Study Institute held in Iceland report on recent advances in superstring theory, which is the leading candidate for a unified description of all known elementary particles and interactions. Chapters examine D-branes in string theory, moduli spaces of Calaba-Yau compactifications, the matrix model of M-theory, the holographic principle, Born-Infeld actions and D-brane physics, superconformal quantum mechanics and multi-black hole moduli spaces, large-N gauge theories, random surfaces, and Lorentzian and Euclidean quantum gravity. The editors are affiliated with the Science Institute of the University of Iceland. Annotation copyrighted by Book News, Inc., Portland, OR

Quantum Triangulations

Quantum Triangulations
Author: Mauro Carfora
Publisher: Springer Science & Business Media
Total Pages: 298
Release: 2012-01-14
Genre: Science
ISBN: 3642244408

Research on polyhedral manifolds often points to unexpected connections between very distinct aspects of Mathematics and Physics. In particular triangulated manifolds play quite a distinguished role in such settings as Riemann moduli space theory, strings and quantum gravity, topological quantum field theory, condensed matter physics, and critical phenomena. Not only do they provide a natural discrete analogue to the smooth manifolds on which physical theories are typically formulated, but their appearance is rather often a consequence of an underlying structure which naturally calls into play non-trivial aspects of representation theory, of complex analysis and topology in a way which makes manifest the basic geometric structures of the physical interactions involved. Yet, in most of the existing literature, triangulated manifolds are still merely viewed as a convenient discretization of a given physical theory to make it more amenable for numerical treatment. The motivation for these lectures notes is thus to provide an approachable introduction to this topic, emphasizing the conceptual aspects, and probing, through a set of cases studies, the connection between triangulated manifolds and quantum physics to the deepest. This volume addresses applied mathematicians and theoretical physicists working in the field of quantum geometry and its applications.

Applied Differential Geometry: A Modern Introduction

Applied Differential Geometry: A Modern Introduction
Author: Vladimir G Ivancevic
Publisher: World Scientific
Total Pages: 1346
Release: 2007-05-21
Genre: Mathematics
ISBN: 9814475645

This graduate-level monographic textbook treats applied differential geometry from a modern scientific perspective. Co-authored by the originator of the world's leading human motion simulator — “Human Biodynamics Engine”, a complex, 264-DOF bio-mechanical system, modeled by differential-geometric tools — this is the first book that combines modern differential geometry with a wide spectrum of applications, from modern mechanics and physics, via nonlinear control, to biology and human sciences. The book is designed for a two-semester course, which gives mathematicians a variety of applications for their theory and physicists, as well as other scientists and engineers, a strong theory underlying their models.

Applied Differential Geometry

Applied Differential Geometry
Author: Vladimir G. Ivancevic
Publisher: World Scientific
Total Pages: 1346
Release: 2007
Genre: Geometry
ISBN: 9812770720

Introduction -- Technical preliminaries: tensors, actions and functors -- Applied manifold geometry -- Applied bundle geometry -- Applied jet geometry -- Geometrical path integrals and their applications

Geometry from Dynamics, Classical and Quantum

Geometry from Dynamics, Classical and Quantum
Author: José F. Cariñena
Publisher: Springer
Total Pages: 739
Release: 2014-09-23
Genre: Science
ISBN: 9401792208

This book describes, by using elementary techniques, how some geometrical structures widely used today in many areas of physics, like symplectic, Poisson, Lagrangian, Hermitian, etc., emerge from dynamics. It is assumed that what can be accessed in actual experiences when studying a given system is just its dynamical behavior that is described by using a family of variables ("observables" of the system). The book departs from the principle that ''dynamics is first'' and then tries to answer in what sense the sole dynamics determines the geometrical structures that have proved so useful to describe the dynamics in so many important instances. In this vein it is shown that most of the geometrical structures that are used in the standard presentations of classical dynamics (Jacobi, Poisson, symplectic, Hamiltonian, Lagrangian) are determined, though in general not uniquely, by the dynamics alone. The same program is accomplished for the geometrical structures relevant to describe quantum dynamics. Finally, it is shown that further properties that allow the explicit description of the dynamics of certain dynamical systems, like integrability and super integrability, are deeply related to the previous development and will be covered in the last part of the book. The mathematical framework used to present the previous program is kept to an elementary level throughout the text, indicating where more advanced notions will be needed to proceed further. A family of relevant examples is discussed at length and the necessary ideas from geometry are elaborated along the text. However no effort is made to present an ''all-inclusive'' introduction to differential geometry as many other books already exist on the market doing exactly that. However, the development of the previous program, considered as the posing and solution of a generalized inverse problem for geometry, leads to new ways of thinking and relating some of the most conspicuous geometrical structures appearing in Mathematical and Theoretical Physics.

Lumen Naturae

Lumen Naturae
Author: Matilde Marcolli
Publisher: MIT Press
Total Pages: 390
Release: 2020-05-26
Genre: Mathematics
ISBN: 0262358328

Exploring common themes in modern art, mathematics, and science, including the concept of space, the notion of randomness, and the shape of the cosmos. This is a book about art—and a book about mathematics and physics. In Lumen Naturae (the title refers to a purely immanent, non-supernatural form of enlightenment), mathematical physicist Matilde Marcolli explores common themes in modern art and modern science—the concept of space, the notion of randomness, the shape of the cosmos, and other puzzles of the universe—while mapping convergences with the work of such artists as Paul Cezanne, Mark Rothko, Sol LeWitt, and Lee Krasner. Her account, focusing on questions she has investigated in her own scientific work, is illustrated by more than two hundred color images of artworks by modern and contemporary artists. Thus Marcolli finds in still life paintings broad and deep philosophical reflections on space and time, and connects notions of space in mathematics to works by Paul Klee, Salvador Dalí, and others. She considers the relation of entropy and art and how notions of entropy have been expressed by such artists as Hans Arp and Fernand Léger; and traces the evolution of randomness as a mode of artistic expression. She analyzes the relation between graphical illustration and scientific text, and offers her own watercolor-decorated mathematical notebooks. Throughout, she balances discussions of science with explorations of art, using one to inform the other. (She employs some formal notation, which can easily be skipped by general readers.) Marcolli is not simply explaining art to scientists and science to artists; she charts unexpected interdependencies that illuminate the universe.

Quantum Gravity and Quantum Cosmology

Quantum Gravity and Quantum Cosmology
Author: Gianluca Calcagni
Publisher: Springer
Total Pages: 402
Release: 2012-10-31
Genre: Science
ISBN: 3642330363

Quantum gravity has developed into a fast-growing subject in physics and it is expected that probing the high-energy and high-curvature regimes of gravitating systems will shed some light on how to eventually achieve an ultraviolet complete quantum theory of gravity. Such a theory would provide the much needed information about fundamental problems of classical gravity, such as the initial big-bang singularity, the cosmological constant problem, Planck scale physics and the early-time inflationary evolution of our Universe. While in the first part of this book concepts of quantum gravity are introduced and approached from different angles, the second part discusses these theories in connection with cosmological models and observations, thereby exploring which types of signatures of modern and mathematically rigorous frameworks can be detected by experiments. The third and final part briefly reviews the observational status of dark matter and dark energy, and introduces alternative cosmological models. Edited and authored by leading researchers in the field and cast into the form of a multi-author textbook at postgraduate level, this volume will be of benefit to all postgraduate students and newcomers from neighboring disciplines wishing to find a comprehensive guide for their future research.