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Related papers: New subluminal and superluminal spacetime measures

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The asymmetry in the time delay for light rays propagating on opposite sides of a spinning body is analyzed. A frequency shift in the perceived signals is found. A practical procedure is proposed for evidencing the asymmetry, allowing for a…

General Relativity and Quantum Cosmology · Physics 2009-11-10 A. Tartaglia , M. L. Ruggiero

Special relativity turns out to be more than coordinate transformations in which the constancy of the speed of light plays the central role between two inertial reference frames. Special relativity, in essence, is a theory of…

General Physics · Physics 2007-06-13 M. Sultan Parvez

Cosmological observations usually map our present-day past light cone. However, it is also possible to compare different past light cones. This is the concept behind the redshift drift, a model-independent probe of fundamental cosmology. In…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-12 C. S. Alves , A. C. O. Leite , C. J. A. P. Martins , J. G. B. Matos , T. A. Silva

We study the influence of the angle between the two dipole transition moments on the group velocity for two kinds of three-level V-type systems with spontaneously generated coherence and incoherent pumping. The group velocity of the probe…

Optics · Physics 2014-08-06 Olimpia Budriga

Astronomical transients are stellar objects that become temporarily brighter on various timescales and have led to some of the most significant discoveries in cosmology and astronomy. Some of these transients are the explosive deaths of…

Machine Learning · Computer Science 2021-12-20 Daniel Muthukrishna , Kaisey S. Mandel , Michelle Lochner , Sara Webb , Gautham Narayan

The conventional discussion of apparent distortions of space and time in Special Relativity (the Lorentz-Fitzgerald Contraction and Time Dilatation) is extended by considering observations of : (i) moving objects of limited lifetime in…

Popular Physics · Physics 2009-10-01 J. H. Field

A new type of soliton with controllable speed is constructed generalizing the theory of slow-light propagation to an integrable regime of nonlinear dynamics. The scheme would allow the quantum-information transfer between optical solitons…

Quantum Physics · Physics 2007-05-23 Ulf Leonhardt

We discuss some properties of Lorentz invariant theories which allow for superluminal motion. We show that, if signals are always sent forward in time, closed curves along which signals propagate can be formed. This leads to problems with…

Astrophysics · Physics 2007-06-28 Camille Bonvin , Chiara Caprini , Ruth Durrer

We study the spectrum of bosonic strings in the light-like linear dilaton background and find discrete states. These are physical states which exist only at specific values of momentum. All except one discrete states generate spacetime…

High Energy Physics - Theory · Physics 2008-11-26 Pei-Ming Ho , Sheng-Yu Darren Shih

We present a toy metric of spacetime travel from topological change. A bubble-like baby universe is detached and re-attached from our universe. Depending on where the bubble is re-attached, matter may travel superluminally or…

General Relativity and Quantum Cosmology · Physics 2024-06-17 Tingqi Cai , Yi Wang

The nature of quantum nonlocality, as exemplified by entanglement, remains one of the deepest mysteries in quantum physics, challenging classical notions of causality and locality. In this work, we introduce the concept of dark space-time,…

General Physics · Physics 2025-04-29 Arun Kumar Pati

The present work aims to search for an implementation of a new symmetry in the space-time by introducing the idea of an invariant minimum speed scale ($V$). Such a lowest limit $V$, being unattainable by the particles, represents a…

General Relativity and Quantum Cosmology · Physics 2017-11-27 Cláudio Nassif

The results from the Supernova Cosmology Project indicate a relation between cosmic distance and redshift that corresponds to an accelerating Universe, and, as a consequence, the presence of an energy component with negative pressure. This…

Astrophysics · Physics 2007-05-23 Daniel Enstrom , Sverker Fredriksson , Johan Hansson

We develop a formal framework for the behavioral comparison of linear systems across different time domains. We accomplish this by introducing the notion of system interpolation, which determines whether the input-state trajectories of a…

Optimization and Control · Mathematics 2026-02-26 Armin Pirastehzad , Bart Besselink

We pinpoint how a subatomic particle with non-zero mass may attain, in principle, velocities faster-than-light by travelling in helical motion in the limit of very large momentum. This is an educated guess by virtue of the MINOS and OPERA…

General Physics · Physics 2011-10-06 E. Canessa

We consider rectilinear free-space propagation of electromagnetic wavepackets using electromagnetic field theory, scalar wavepacket propagation, and quantum-mechanical formalism. We demonstrate that spatially localized wavepackets are…

Quantum Physics · Physics 2026-05-12 Konstantin Y. Bliokh

General relativity can be formally derived as a flat spacetime theory, but the consistency of the resulting curved metric's light cone with the flat metric's null cone has not been adequately considered. If the two are inconsistent, then…

General Relativity and Quantum Cosmology · Physics 2016-08-31 J. Brian Pitts , W. C. Schieve

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

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

General relativity lacks the notion of the speed of gravity. This is inconvenient and the present paper is aimed at filling this gap up. To that end I introduce the concept of the "alternative" and argue that its variety called the…

General Relativity and Quantum Cosmology · Physics 2015-06-22 S. Krasnikov

A generalisation to electrodynamics and Yang-Mills theory is presented that permits computation of the speed of light. The model presented herewithin indicates that the speed of light in vacuo is not a universal constant. This may be…

High Energy Physics - Theory · Physics 2007-05-23 M. Temple-Raston