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Related papers: Refocusing of Light Rays in Space-Time

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A new causal boundary, which we will term the $l$-boundary, inspired by the geometry of the space of light rays and invariant by conformal diffeomorphisms for space-times of any dimension $m\geq 3$, proposed by one of the authors (R.J. Low,…

General Relativity and Quantum Cosmology · Physics 2022-07-05 A. Bautista , A. Ibort , J. Lafuente , R. Low

This paper reviews and extends an approach to superluminal kinematics set forth by R. Sutherland and J. Shepanski in 1986. This theory is characterized by a spacetime with positive definite metric, a Lorentz factor of the form…

History and Philosophy of Physics · Physics 2023-08-09 Kent A. Peacock

One of the concepts of Relativity theory that challenges conventional intuition the most is time dilation and length contraction. Usual approaches for describing relativistic effects in quantum systems merely postulate the consequences of…

Quantum Physics · Physics 2024-02-27 Esteban Martínez-Vargas

In this second paper, I construct a limit space of a Cauchy sequence of globally hyperbolic spacetimes. In the second section, I work gradually towards a construction of the limit space. I prove the limit space is unique up to isometry. I…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Johan Noldus

The first principles analysis of the radiation by an arbitrary source in a flat Friedmann-Robertson-Walker space-time is presented. The obtained analytical solution explicitly shows that the cosmological redshift is not of kinematic origin…

Classical Physics · Physics 2009-07-03 Neil V. Budko

An interpretation of the inertial mass increase due to an object's velocity which is derived from the theory of special relativity is discussed. A Lorentz transformation of the reference time causes the inertial mass increase. It is assumed…

General Physics · Physics 2008-03-12 Masanori Sato

The special theory of relativity teaches us that, although distinct inertial frames perceive the same dynamical laws, space and time intervals differ in value. We revisit the problem of time contraction using the paradigmatic model of a…

Quantum Physics · Physics 2020-05-21 Matheus Fritsch Savi , Renato Moreira Angelo

Adopting the strong field limit approach, we investigate the strong gravitational lensing of a spherically symmetric spacetime in the Einstein-Proca theory. With the strong field limit coefficient, three observable quantities are obtained,…

General Physics · Physics 2015-07-19 Guoping Li , Yan Zhang , Li Zhang , Zhongwen Feng , Xiaotao Zu

We live in a 3+1 space-time that is intended as a description of the universe with three space dimensions and one time dimension. Space-time dimensionality seems so natural that it is rarely criticized. Experiments and the highly successful…

General Physics · Physics 2009-11-10 Giorgio Fontana

The aim of this survey is to give an overview on the geometry of Einstein maximal globally hyperbolic 2+1 spacetimes of arbitrary curvature, conatining a complete Cauchy surface of finite type. In particular a specialization to the finite…

Differential Geometry · Mathematics 2007-05-23 Riccardo Benedetti , Francesco Bonsante

In this work we will focus on the causal character of Carter Spacetime (see B. Carter, Causal structure in space-time, Gen. Rel. Grav. 1 4 337-406, 1971). The importance of this spacetime is the following: for the causally best well behaved…

General Relativity and Quantum Cosmology · Physics 2015-07-30 Oihane F. Blanco , Andrea Moreira

By definition a spacetime is stably causal if it is possible to widen the light cones all over the spacetime without spoiling causality. We prove that if the spacetime is at least non-total imprisoning then it is stably causal provided the…

General Relativity and Quantum Cosmology · Physics 2009-08-12 E. Minguzzi , M. Rinaldelli

We present a Lorentz gauge theory of gravity in which the metric is not dynamical. Spherically symmetric weak field solutions are studied. We show that this solution contains the Schwarzschild spacetime at least to the first order of…

General Relativity and Quantum Cosmology · Physics 2016-10-27 Ahmad Borzou

The closed-universe recollapse conjecture is studied for the spherically symmetric spacetimes. It is proven that there exists an upper bound to the lengths of timelike curves in any Tolman spacetime that possesses $S^3$ Cauchy surfaces and…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Gregory A. Burnett

A modified gravitational model whose action is given by an arbitrary function of the Ricci scalar, the matter Lagrangian density, a scalar field, and its kinetic term is investigated as an extension of the gravitational sector including an…

General Relativity and Quantum Cosmology · Physics 2026-05-21 Faizuddin Ahmed , A. F. Santos

Contrary to what is often stated, a fundamental spacetime discreteness need not contradict Lorentz invariance. A causal set's discreteness is in fact locally Lorentz invariant, and we recall the reasons why. For illustration, we introduce a…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Fay Dowker , Joe Henson , Rafael D. Sorkin

We show how the Minkowskian space-time emerges from a topologically homogeneous causal network, presenting a simple analytical derivation of the Lorentz transformations, with metric as pure event-counting. The derivation holds generally for…

General Relativity and Quantum Cosmology · Physics 2010-09-27 Giacomo Mauro D'Ariano , Alessandro Tosini

If textbook Lorentz invariance is actually a property of the equations describing a sector of matter above some critical distance scale, several sectors of matter with different critical speeds in vacuum can coexist and an absolute rest…

General Physics · Physics 2008-02-03 Luis Gonzalez-Mestres

According to the Lorentz transformation and clearly seen from the Minkowski diagram, hyperbolic spacetime motion of a test object relative to a stationary reference frame can be performed in a specific way such that time becomes frozen in…

General Physics · Physics 2011-08-25 Arne Bergstrom

Flat space-time has not heretofore been thought a suitable locus in which to construct model universes because of the presumed necessity of incorporating gravitation in such models and because of the historical lack of a theory of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Wasley S. Krogdahl