Showing papers on "Four-force published in 1993"

Introducing Einstein's Relativity

Abstract: PART A: SPECIAL RELATIVITY PART B: THE FORMALISM OF TENSORS PART C: GENERAL RELATIVITY PART D: BLACK HOLES PART E: GRAVITATIONAL WAVES PART F: COSMOLOGY

The attraction of gravitation: New studies in the history of general relativity

Abstract: PART 1 DISPUTES WITH EINSTEIN: Einstein and Nordstrom - Some Lesser Known Thought Experiments in Gravitation, John D. Norton Out of the Labyrinth? Einstein, Hertz, and the Gottingen Answer to the Hole Argument, Don Howard and John Norton Conservation Laws and Gravitational Waves in General Relativity (1915-1918), Carlo Cattani and Michelangelo De Maria The General Relativistic Two-Body Problem and the Einstein-Silberstein Controversy, Peter Havas. PART 2 THE EMPIRICAL BASIS OF GENERAL RELATIVITY: Einstein's Explanation of the Motion of Mercury's Perihelion, John Eannan and Michel Janssen Pieter Zeeman's Experiments on the Equality of Inertial and Gravitational Mass, A. J. Kox. PART 3 VARIATIONAL PRINCIPLES IN GENERAL RELATIVITY: Variational Derivations of Einstein's Equations, S. Kichenassamy Levi-Civita's Influence on Palatini's Contribution to General Relativity, Carlo Cattani. PART 4 THE RECEPTION AND DEVELOPMENT OF GENERAL RELATIVITY: The American Contribution the the Theory of Differential Invariants, Katin Reich The Reaction to Relativity Theory in Germany III - Hundred Authors Against Einstein, Hubert Goenner Attempts at Unified Field Theories (1919-1955). Alleged Failure and Intrinsic Validation/Refutation Criteria, Silvio Bergia Vladimir Fock - Philosophy of Gravity and Gravity of Philosophy, Gennady Gorelik S. Chandrasekhar's Contributions to General Relativity, Kameshwar C. Wali. PART 5 COSMOLOGY AND GENERAL RELATIVITY: Lemaitre and the Schwarzschild Solution, Jean Eisenstaedt E. A. Milne and the Origins of Modern Cosmology - An Essential Presence, John Urani and George Gale.

Covariant definition of inertial forces

Abstract: We present a covariant definition of inertial forces in general relativity (gravitational, centrifugal, Euler and Coriolis-Lense-Thirring) which is valid in all spacetimes including ones with no symmetry.

Scalar gravitation: A laboratory for numerical relativity.

Abstract: While not a correct physical theory, relativistic scalar gravitation provides a simple test site for developing many of the tools of numerical relativity. In contrast with general relativity, scalar gravitation allows gravitational waves to be generated in spherical symmetry. Hence one needs only one spatial dimension to try out methods of calculating wave emission and propagation. Using this theory, we have built a mean-field particle simulation scheme to study the dynamical behavior of collisionless matter in spherical symmetry. We find that we are able to calculate smooth and accurate wave forms, despite the stochastic representation of the matter source terms caused by sampling with a finite number of particles. A similar scheme should provide accurate wave forms in general relativity, provided sufficient computer resources are used.

Mathematical Theory of the Origin of Matter

Abstract: It is shown that from a simple and elegant action it is possible to obtain: (i) the equations of classical dynamics, (ii) Schrodinger's equation, (iii) the dynamical equation of special relativity, (iv) scale-invariant gravitation including general relativity, (v) the mathematical theory of the origin of matter, and (vi) the potential function of inflationary theory. When the action term in question is related to the electromagnetic theory an ugly feature arises, however. There must be a multiplication by a small dimensionless number of order 10−38. If this ugly feature is to be avoided, matter must be taken to originate, not as particles observed in the laboratory but as Planck particles. The decay of each such particle into ≈ 1019 hadrons then explains the genesis of numbers of order 1038 that appear in physics and cosmology. It also raises questions concerning primordial nucleosynthesis which were discussed in the preceding paper.

An axiomatization of general relativity

Abstract: An axiomatization of the general theory of relativity is proposed. The assumed philosophical background is critical realism. None of the “principles” commonly considered as founding the theory, such as (a) the equality of inertial and gravitational mass, (b) the principle of equivalence, (c) the principle of general covariance, (d) the geodesic postulate, and (e) Mach's principle, are taken as axioms in our system.

General Relativity as a Theory of Two Connections

Abstract: We show in this paper that it is possible to formulate General Relativity in a phase space coordinatized by two SO(3) connections. We analyze first the Husain-Kuchayr model and find a two connection description for it. Introducing a suitable scalar constraint in this phase space we get a Hamiltonian formulation of gravity that is close to the Ashtekar one, from which it is derived, but has some interesting features of its own. Among them a possible mechanism for dealing with the degenerate metrics and a neat way of writing the constraints of General Relativity.

The physical meaning of canonical quantization in terms of reference systems

Abstract: The canonical approach to general relativity in terms of reference systems is discussed to show that Einstein's principles of equivalence and general relativity imply the physical insignificance of quantized general relativity. In particular it is demonstrated that even the (anholonomic) flat-space canonical formalism leads to physically uninterpretable results. This lack of quantum content of general relativity is reflected by Rosenfeld's uncertainty relations and can especially be removed by modifying general relativity in the spirit of classical Einstein-Cartan theory with teleparallelism.

General-relativistic cosmology with expansion and rotation

Abstract: A model of an expanding and rotating universe is constructed in the framework of general relativity. The parameters of the model are compared with the fundamental observables and shown to be in good agreement.

On the Meaning of Special Relativity If a Fundamental Frame Exists

Abstract: The physical foundations of the theory of special relativity are critically examined from the point of view that a fundamental inertial frame exists in nature. This idea is implicit in the older works of Lorentz and Fitzgerald, and in more recent work by Janossy, Builder, Prokhovnik, Bell and others. Even in the event of modifications to the theory, certain elements will have to be retained: the usual relativistic formulae for energy and momentum, the full equivalence of mass and energy, the idea of c as a limit velocity, Lorentz contraction and time dilation of moving bodies.

Local Automorphism Invariance: a Generalization of General Relativity

Abstract: I propose a generalization of the Principle of Equivalence, upon which General Relativity is founded. General Relativity may be viewed as a gauge theory of local Lorentz invariance in the tangent space. The condition that the covariant derivatives of the Clifford algebra generators vanish, ∇ϕγν=0, then insures that the Riemann condition is satisfied, ∇ϕgρσ=0, and that the Riemann curvature tensor is identical to the field strength tensor for the gauge fields. I propose to extend local Lorentz invariance to the further demand of local automorphism invariance of the Clifford algebra. Local automorphism invariance is equivalent to allowing the basis spinors of the spinor space to be chosen locally, just as local Lorentz invariance is equivalent to allowing the basis vectors of the tangent space to be chosen locally. Consequently, the Clifford algebra generators are found not to have vanishing total covariant derivative, that is ∇ϕγν≠0, in contrast to the case of General Relativity. The additional dynamical degrees of freedom of the Clifford algebra generators may be conveniently prescribed to reside in drehbeins ("spin-legs"), these constituting the trans formation matrix between the local spinor basis and an arbitrarily assigned but constant spinorbasis. For the case of four-dimensional spacetime considered herein, the automorphism group is the conformal group, and therefore this theory may be viewed as a spinor inspired conformal extensionof General Relativity. However, if we treat this theory as an ordinary gauge theory, then the actiondoes not contain the Einstein-Hilbert term (that is, a term linear in the Ricci scalar). Nevertheless, I argue that the Einstein-Hilbert action, along with the mass of the spinor field and masses for some of the gauge fields, may all arise together as a symmetry breaking phenomenon in which the ground state is only invariant under Lorentz transformations

Einstein, Lorentz, Leiden and general relativity

Abstract: The work on general relativity done in the Netherlands in the period of 1915-1920 is briefly reviewed and its importance for the development of general relativity is discussed.

The difference between Newtonian and relativistic forces

Abstract: This paper discusses a new turn in the 148-year old electrodynamic force law controversy between the 1822 Ampere force law of the Newtonian electrodynamics and Grassmann's 1845 law which has become the electrodynamic force law of relativistic electromagnetism. Faced with the infallibility of Ampere's empirical law, defenders of relativity theory now argue that Ampere's law is “equivalent” to the relativistic law. This paper demonstrates that, far from being equivalent, the laws require two different mechanics of solid bodies, disagree on internally generated stresses, and predict different force distributions.

(1+1)-Dimensional Methods for General Relativity

Abstract: This is an article contributed to the Brill Festschrift, in honor of the 60th birthday of Prof. D.R. Brill, which will appear in the Vol.2 of the Proceedings of the International Symposia on Directions in General Relativity. In this article we present the (1+1)-dimensional method for studying general relativity of 4-dimensions. We first discuss the general formalism, and subsequently draw attention to the algebraically special class of space-times, following the Petrov classification. It is shown that this class of space-times can be described by the (1+1)-dimensional Yang-Mills action interacting with matter fields, with the spacial diffeomorphisms of the 2-surface as the gauge symmetry. The constraint appears polynomial in part, whereas the non-polynomial part is a non-linear sigma model type in (1+1)-dimensions. It is also shown that the representations of $w_{\infty}$-gravity appear naturally as special cases of this description, and we discuss briefly the $w_{\infty}$-geometry in term of the fibre bundle.

Relativity In Our Time: From Physics to Human Relations

Abstract: Introduction: a seminal idea - the principle of relativity toward an abstract view of nature Einstein's ideas of special relativity the principle of relativity - from Galileo to Einstein relative time and the twin paradox the Mach Principle the curvature of space-time gravitation and crucial tests of general relativity Faraday's unified field concept the night sky cosmology.