Spin In Gravity Is It Possible To Give An Experimental Basis To Torsion

The introduction of spin is believed to be a necessary tool if one wishes to quantize general relativity. Then the main problem is to see if the introduction of spin generalizing the general relativity from a geometric point of view, i.e. through the concept of torsion, can be experimentally verified.The reader can find in this book both theoretical and experimental arguments which show the necessity for the introduction of spin, and then of torsion, in gravity. In fact, torsion constitutes the more natural and simple way to introduce spin in general relativity. For that reason it is of fundamental importance to see if there are some experiences that indicate — if not directly, then at least indirectly — the presence of torsion. This book presents a discussion on experiments with a polarized-mass torsion pendulum, the search for galactic dark matter interacting with a spin pendulum, a description of a space-based method for determination of the gravitational constant and space-based measurements of spin in gravity, as well as a discussion on theoretical arguments, for instance the nature of torsion and nonmetricity, the viability of gravitational theories with spin-torsion and spin-spin interaction, many-dimensional gravitational theories with torsion, spinors on curved spaces, the spinors in real space-time, etc.We know that until now there has been no evidence for torsion, but this fact cannot prevent us from considering in some detail this implement of research that seems to be important from both a geometrical and a physical point of view.

The introduction of spin is believed to be a necessary tool if one wishes to quantize general relativity. Then the main problem is to see if the introduction of spin generalizing the general relativity from a geometric point of view, i.e. through the concept of torsion, can be experimentally verified. The reader can find in this book both theoretical and experimental arguments which show the necessity for the introduction of spin, and then of torsion, in gravity. In fact, torsion constitutes the more natural and simple way to introduce spin in general relativity. For that reason it is of fundamental importance to see if there are some experiences that indicate -- if not directly, then at least indirectly -- the presence of torsion. This book presents a discussion on experiments with a polarized-mass torsion pendulum, the search for galactic dark matter interacting with a spin pendulum, a description of a space-based method for determination of the gravitational constant and space-based measurements of spin in gravity, as well as a discussion on theoretical arguments, for instance the nature of torsion and nonmetricity, the viability of gravitational theories with spin -- torsion and spin-spin interaction, many-dimensional gravitational theories with torsion, spinors on curved spaces, the spinors in real space -- time, etc. We know that until now there has been no evidence for torsion, but this fact cannot prevent us from considering in some detail this implement of research that seems to be important from both a geometrical and a physical point of view.

An up-to-date description of progress and current problems with the gravitational constant, both in terms of generalized gravitational theories and experiments either in the laboratory, using Casimir force measurements, or in space at solar system distances and in cosmological observations. Contributions cover different aspects of the state and prediction of unified theories of the physical interactions including gravitation as a cardinal link, the role of experimental gravitation and observational cosmology in discriminating between them, the problem of the precise measurement and stability of fundamental physical constants in space and time, and the gravitational constant in particular. Recent advances discussed include unified and scalar-tensor theories, theories in diverse dimensions and their observational windows, gravitational experiments in space, rotational and torsional effects in gravity, basic problems in cosmology, early universe as an arena for testing unified models, and big bang nucleosynthesis.

Bringing geometric algebra to the mainstream of physics pedagogy, Geometric Algebra and Applications to Physics not only presents geometric algebra as a discipline within mathematical physics, but the book also shows how geometric algebra can be applied to numerous fundamental problems in physics, especially in experimental situations. This

In this XVII Course of the International School of Cosmology and Gravitation devoted to "ADVANCES IN THE INTERPLAY BETWEEN QUANTUM AND GRAVITY PHYSICS" we have considered different aspects of the influence of gravity on quantum systems. In order to achieve this aim, in many lectures, seminars and discussions we have strengthened the interplay between gravity and quantum systems starting from the situation in the early universe based on astrophysical observations, up to the earthly based experiments with atom interferometry for probing the structure of space-time. Thus we have had timely lectures on the quantum field and horizon of a black hole including reviews of the problem of black holes thermodynamics and entropy, quantum information, quantum black holes, quantum evaporation and Hawking radiation, recent advances in stockastic gravity. We have also discussed quantum fluctuations in inflationary universe, quantum effects and reheating after inflation, and superplanckian energies in Hawking radiation. In this regard the subject of spinors in purely affine space-time and Dirac matter according to Weyl in the generalized theory of gravitation were developed . The dualism between space-time and matter has been deeply analyzed in order to see why, for general relativity, this is an obstacle for quantization of the theory. Also canonical Gravity and Mach's principle, torsion and curvature as commutator for Quantum Gravity and Dirac Geometry of real space-time were analysed, together with the problem of 5-Dimensional Projective Unified Field theory and Multidimensional Gravity and Cosmology.

This book provides an up-to-date understanding of the progress and current problems of the interplay of nonlocality in the classical theories of gravitation and quantum theory. These problems lie on the border between general relativity and quantum physics, including quantum gravity.

This book provides an up-to-date understanding of the progress and current problems of the interplay of nonlocality in the classical theories of gravitation and quantum theory. These problems lie on the border between general relativity and quantum physics, including quantum gravity. Contents:Bohr's and Mach's Conceptions of Non-locality in Gravitation (H H v Borzeszkowski & H-J Treder)Non-locality Versus Locality: The Epistemological Background of the Einstein–Bohr Debate (H-H v Borzeszkowski & R Wahsner)Global Energy and Non-local Energy (J N Goldberg)Aspects of Physical Non-locality (A Komar)The EPR Argument and Quantum Non-locality (B K Datta et al.)Non-commuting Geometry and Spin Fluctuations (V de Sabbata et al.)Noncommutative Geometry for Pedestrians (J Madore)Some Topics and Trials on the Theory of Non-local Fields — Theory of Fields in Finsler Spaces and Fluctuations of Space–Time (Y Takano)Quantum Gravity Phenomenology (D V Nanopoulos)Hawking Radiation in String Theory and the String Phase of Black Holes (M R Medrano & N Sanchez)Non-locality, Entanglement and Quantum Computers (Z-L Zhang & Z-J Zhang) Readership: Cosmologists, astronomers, astrophysicists, high energy physicists and experimental physicists. Keywords:Nonlocality;Gravitation;Quantum Theory;General Relativity;Quantum Gravity

The book is aimed at assessing the capabilities of state-of-the-art optical techniques in elucidating the fundamental electronic and structural properties of semiconductor and metal surfaces, interfaces, thin layers, and layer structures, and assessing the usefulness of these techniques for optimization of high quality multilayer samples through feedback control during materials growth and processing. Particular emphasis is dedicated to the theory of nonlinear optics and to dynamical processes through the use of pump–probe techniques together with the search for new optical sources. Some new applications of Scanning Probe Microscopy to Material Science and biological samples, dried and in vivo, with the use of different laser sources are also presented. Materials of particular interest are silicon, semiconductor–metal interfaces, semiconductor and magnetic multi-layers and III-V compound semiconductors. Contents:Epitaxial-Like Growth of Lead Phthalocyanine Layers on GaAs(001) Surfaces (L Riele, B Buick, E Speiser, B-O Fimland, P Vogt and W Richter)Optical Properties of Nanostructured Metamaterials (E Cortes, B S Mendoza, W L Mochan and G Ortiz)Ab Initio Long-Wavelength Properties of Metallic Systems: Iron and Magnesium (M Cazzaniga, L Caramella, N Manini, P Salvestrini and G Onida)Magnetic Second-Harmonic Generation from Interfaces and Nanostructures (J F McGilp)Optical Investigations of the Interface Formation between Organic Molecules and Semiconductor Surfaces (T Bruhn, L Riele, B-O Fimland, N Esser and P Vogt)Reflection Anisotropic Spectroscopy Studies of Thiolate/Metal Interfaces (D S Martin)The Physics of X-ray Free Electron Lasers (X-FELs): An Elementary Approach (P Rebernik Ribic and G Margaritondo)The Decisive Role of Interface Phonons in Polaron State Formation in Quantum Nanostructures (A Yu Maslov and O V Proshina)Dielectric Analysis on Optical Properties of Silver Nano Particles in ZrO2 Thin Film Prepared by Sol–Gel Method (M Wakaki and E Yokoyama)Towards Ab Initio Calculation of the Circular Dichroism of Peptides (E Molteni, G Onida and G Tiana)Dynamics and Spectral Properties of Free-Standing Negatively-Curved Carbon Surfaces (M De Corato and G Benedek) Readership: The book is a good reference for researchers that want to be involved in optical spectroscopy as a tool to study surfaces and interfaces. Keywords:Optics;Spectroscopy;Surfaces;Semiconductors;Reflectivity