For seventy years, we have known that Einstein's theory is essentially a theory of propagation of waves for the gravitational field. Confusion enters, however, through the fact that the word wave, in physics, implies sometimes repetition and sometimes not. This confusion is often increased by he use of Fourier transforms, by which a disturbanse which appears to be without repetition is resolved into periodic wave-trains with all frequencies. But, in a general curved space-time, we have nothing corresponding to Fourier transforms. Here, we consider systematically waves corresponding to the propagation of discontinuities of physical quantities describing either fields (essentially electromagnetic fields and gravitational field), or the motion of a fluid, or together, in magnetohydrodynamics, the changes in time of a field and of a fluid. The main equations, for the different studied phenomena, constitute a hyperbolic system and the study of a formal Cauchy problem is possible. We call ordinary waves the case in which the derivative of superior order appearing in the system are discontinuous at the traverse of a hypersurface, the wave front ; we call shock waves the case where the derivatives of an order inferior by one are discontinuous at the traverse of a wave front. XI xii PREFACE From 1950, many well-known scientits (Taub, Synge, Choquet-B ruhat, etc.) have studied the corresponding equations for different physical phenomena : systems associated to the electromagnetic and gravitational fields, to hydrodynamics and to magnetohydrodynamics.

Solar-terrestrial physics deals with phenomena in the region of space between the surface of the Sun and the upper atmosphere of the Earth, a region dominated by matter in a plasma state. This area of physics describes processes that generate the solar wind, the physics of geospace and the Earth's magnetosphere, and the interaction of magnetospheri

Magnetohydrodynamic Processes in The Solar Plasma provides comprehensive and up-to-date theory and practice of the fundamentals of heliospheric research and the Sun's basic plasma processes, covering the dynamics of the solar interior to its exterior in the framework of magnetohydrodynamics. The book covers novel aspects of solar and heliospheric physics, astrophysics and space science, and fundamentals of the fluids and plasmas. Topics covered include key phenomena in the solar interior such as magnetism, dynamo physics, and helioseismology; dynamics and plasma processes in its exterior including fluid processes such as waves, shocks, instabilities, reconnection, and dynamics in the partially ionized plasma; and physics and science related to coronal heating, solar wind, and eruptive phenomena. The content has been developed to specifically cover fundamental physics-related descriptions and up-to-date developments of the scientific research related to these significant topics. The book therefore provides the entire fundamental and front-line research aspects of solar and heliospheric plasma processes, mainly in the context of solar plasma, however, the content also has larger implications for the astrophysical plasma, and laboratory plasma, fluid dynamics, and associated basic theories. It also includes additional supplementary content such as key instruments and experimental techniques in the form of appendices, boxed-off key information highlighting the most fundamental and key aspects, and worked examples with additional question sets.Magnetohydrodynamic Processes in The Solar Plasma covers both the fundamentals of the topics included as well as up-to-date and future developments in this research field, forming an essential, foundational reference for researchers, academics, and advanced students, in the field of solar physics and astrophysics, as well as neighboring disciplines. - Applies fundamental solar science and research in magnetohydrodynamic processes to practice, and uses in teaching and research - Covers the latest developments in solar plasma processes in terms of both theoretical and fundamental aspects. - Includes the large cohort of plasma processes (e.g., waves, shocks, instabilities, reconnection, heating, magnetism, seismology) significant for the diverse scales of the plasmas and fluids. - Provides detailed physical and mathematical descriptions of the theories in each chapter, along with scientific details, which will enhance understanding of basic phenomena and aid in applying the practical content to current research

This book describes Carmeli's cosmological general and special relativity theory, along with Einstein's general and special relativity. These theories are discussed in the context of Moshe Carmeli's original research, in which velocity is introduced as an additional independent dimension. Four- and five-dimensional spaces are considered, and the five-dimensional braneworld theory is presented. The Tully-Fisher law is obtained directly from the theory, and thus it is found that there is no necessity to assume the existence of dark matter in the halo of galaxies, nor in galaxy clusters.The book gives the derivation of the Lorentz transformation, which is used in both Einstein's special relativity and Carmeli's cosmological special relativity theory. The text also provides the mathematical theory of curved space­time geometry, which is necessary to describe both Einstein's general relativity and Carmeli's cosmological general relativity. A comparison between the dynamical and kinematic aspects of the expansion of the universe is made. Comparison is also made between the Friedmann-Robertson-Walker theory and the Carmeli theory. And neither is it necessary to assume the existence of dark matter to correctly describe the expansion of the cosmos.

These lecture notes of the courses presented at the first CIME session 1994 by leading scientists present the state of the art in recent mathematical methods in Nonlinear Wave Propagation.

In the presence of magnetic induction and electrical fields several types of discontinuities may exist in an electrically conducting fluid. These phenomena can be described by the laws of conservation of mass, momentum, and energy; Maxwell's electromagnetic equations, and Ohm's law. Those discontinuities, which can be characterized by the conditions that both the temperature and density change across them are different from zero, are called magneto-hydrodynamic shock waves. This monograph is concerned with the study of these types of discontinuities.

This book focuses on the non-traditional branches of physics and mechanics of shock waves that have arisen recently in connection with the intensive study of these waves in a wide variety of phenomena - from nuclear matter to clusters of galaxies. The book is devoted to the various physical phenomena and properties of intense shock waves. The author addresses methods of generation, diagnostics, as well as theoretical methods for describing shock waves at extremely high pressures and temperatures in laboratory and quasi-laboratory conditions. The state of materials with high energy density generated by shock wave compression is discussed. In addition, the book aims to systematize, generalize, and describe from a universal viewpoint the extensive theoretical and experimental material on the physics of high energy densities - the physics and mechanics of intense shock waves. The book is based on lectures delivered by the author at the Moscow Institute of Physics and Technology, the Higher School of Physics of Rosatom State Nuclear Energy Corporation, as well as overviews presented at many scientific conferences and symposia. It is useful to a wide range of researchers in natural sciences, giving them access to original works and allowing them to navigate the fascinating problems of the modern science of intense shock waves.