Yu. P. Goncharov

Bio: Yu. P. Goncharov is an academic researcher from Saint Petersburg State Polytechnic University. The author has contributed to research in topics: Field (physics) & Quantum chromodynamics. The author has an hindex of 15, co-authored 55 publications receiving 470 citations.

Casimir effect in supergravity theories and the quantum birth of the Universe with non-trivial topology

Abstract: The authors discuss the possibility of obtaining the non-zero one-loop topological Casimir effect in supergravity theories and evaluate it for a number of supergravity models in the flat homogeneous Clifford-Klein spacetimes with topologies Mq=(S1)q*R4-q, q=1, 2, 3. These models are pure N=1 supergravity, N=1 supergravity coupled to matter and gauge fields, N=2 supergravity coupled to matter fields and N=8 supergravity. The results of calculations permit us to estimate the probability of the quantum birth of the Universe, possessing the effective Mq topology and filled with the fields of any of the above theories in the semiclassical approximation. In all cases it turns out that the birth of the Universe with more isotropic topology is more plausible. They also outline the perspectives of an extension of the results obtained.

Black hole physics, confining solutions of su(3)-yang– mills equations and relativistic models of mesons

Abstract: The black hole physics techniques and results are applied to find a set of exact solutions of the SU(3)-Yang–Mills equations in Minkowski space–time in the Lorentz gauge. All the solutions contain only the Coulomb-like or linear in r components of SU(3)-connection. This allows one to obtain some possible exact and approximate solutions of the corresponding Dirac equation that can describe the relativistic bound states. Possible application to the relativistic models of mesons is also outlined.

Topological Casimir effect for a class of hyperbolic three-dimensional Clifford-Klein spacetimes

Abstract: The topological Casimir energy for all topologically inequivalent configurations of a massless real scalar field on the hyperbolic three-dimensional Clifford-Klein spacetimes R*H2/ Gamma is evaluated for the case when H2/ Gamma is a compact Riemannian surface of genus g>1. Calculations are performed at both zero and finite temperature with the help of the Selberg trace formula for compact Riemannian surfaces of genus g>1.

Quantum electrodynamics

Abstract: THE subject of quantum electrodynamics is extremely difficult, even for the case of a single electron. The usual method of solving the corresponding wave equation leads to divergent integrals. To avoid these, Prof. P. A. M. Dirac* uses the method of redundant variables. This does not abolish the difficulty, but presents it in a new form, which may be dealt with in two ways. The first of these needs only comparatively simple mathematics and is directly connected with an elegant general scheme, but unfortunately its wave functions apply only to a hypothetical world and so its physical interpretation is indirect. The second way has the advantage of a direct physical interpretation, but the mathematics is so complicated that it has not yet been solved even for what appears to be the simplest possible case. Both methods seem worth further study, failing the discovery of a third which would combine the advantages of both.

Cosmic Topology

Abstract: General relativity does not allow one to specify the topology of space, leaving the possibility that space is multi-- rather than simply--connected We review the main mathematical properties of multi--connected spaces, and the different tools to classify them and to analyse their properties Following the mathematical classification, we describe the different possible muticonnected spaces which may be used to construct universe models We briefly discuss some implications of multi--connectedness for quantum cosmology, and its consequences concerning quantum field theory in the early universe We consider in details the properties of the cosmological models where space is multi--connected, with emphasis towards observable effects We then review the analyses of observational results obtained in this context, to search for a possible signature of multi--connectedness, or to constrain the models They may concern the distribution of images of cosmic objects like galaxies, clusters, quasars,, or more global effects, mainly those concerning the Cosmic Microwave Background, and the present limits resulting from them

Gauge Theory of Elementary Particle Physics

Abstract: Ta-Pei Cheng and Ling-Fong Li 1984 Clarendon Press: Oxford University Press xi + 536 pp price £35 (£15 paperback) ISBN 0 19 851956 7 Hdbk, 0 19 851961 3Pbk This book is an excellent summary of gauge theories in particle physics, intended for advanced graduate students and research workers in the field. It presupposes both a knowledge of elementary particle phenomenology and of quantum field theory at the level taught in first-year postgraduate lecture courses.

Foundations of Quantum Mechanics

Abstract: General Instructions Write your CANDIDATE NUMBER clearly on each of the THREE answer books provided. If an electronic calculator is used, write its serial number in the box at the top right hand corner of the front cover of each answer book. USE ONE ANSWER BOOK FOR EACH QUESTION. Enter the number of each question attempted in the horizontal box on the front cover of its corresponding answer book. Hand in THREE answer books even if they have not all been used. You are reminded that the Examiners attach great importance to legibility, accuracy and clarity of expression.