English
Related papers

Related papers: Causality in Time-Neutral Cosmologies

200 papers

In the light of some recent results, it is argued that usual concepts of causality and locality are approximations valid at scales greater than the Compton wavelength and corresponding time scales. It follows that the "spooky" non-locality…

Quantum Physics · Physics 2007-05-23 B. G. Sidharth

Generic models in Galileons or Horndeski theory do not have cosmological solutions that are free of instabilities and singularities in the entire time of evolution. We extend this No-Go theorem to a spacetime with torsion. On this more…

High Energy Physics - Theory · Physics 2024-07-22 S. Mironov , M. Valencia-Villegas

We present probabilistic analysis of the Greenberger-Horne-Zeilinger (GHZ) scheme in the contextualist framework, namely under the assumption that distributions of hidden variables depend on settings of measurement devices. On one hand, we…

Quantum Physics · Physics 2010-11-30 Andrei Khrennikov

This paper showed how a simple lumped parameter model of a circuit can yield correct quantum mechanical predictions of its behavior, even when there is quantum entanglement between components of that circuit. It addresses an important…

Quantum Physics · Physics 2017-12-21 Paul J. Werbos

In this paper we introduce a new general framework for the study of phenomenological quantum gravity theories (PQG). The key idea is the introduction of two different types of spacetime, an observer-independent spacetime (modeled by a…

General Relativity and Quantum Cosmology · Physics 2026-04-21 Andrea Bevilacqua , Alice Boldrin

Causal quantum theory assumes that measurements or collapses are well-defined physical processes, localised in space-time, and never give perfectly reliable outcomes and that the outcome of one measurement only influences the outcomes of…

Quantum Physics · Physics 2021-11-09 Adrian Kent

Drawing from the theory of optimal transport we propose a rigorous notion of a causal relation for Borel probability measures on a given spacetime. To prepare the ground, we explore the borderland between causality, topology and measure…

Mathematical Physics · Physics 2020-12-21 Michał Eckstein , Tomasz Miller

Field theories whose full action is Lorentz invariant (or diffeomorphism invariant) can exhibit superluminal behaviors through the breaking of local Lorentz invariance. Quantum induced superluminal velocities are well-known examples of this…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Jean-Philippe Bruneton

The problems connected with a causality of space-time universe and with the paradox of Einstein, Podolsky, and Rosen are considered. A main philosophical problem and its possible solutions are briefly discussed. A concept of unified local…

Quantum Physics · Physics 2007-05-23 Alexander A. Chernitskii

When angular objects in lensing are considered as linear objects, interesting phenomena start happening. Tachyonic caustics are one example. We review that the intrinsic variables of the lens equation are angular variables. We argue that…

Astrophysics · Physics 2007-05-23 Sun Hong Rhie

The difficulty of explaining non-local correlations in a fixed causal structure sheds new light on the old debate on whether space and time are to be seen as fundamental. Refraining from assuming space-time as given a priori has a number of…

Quantum Physics · Physics 2018-01-15 Ämin Baumeler , Stefan Wolf

We consider the problem of deriving the no-signaling condition from the assumption that, as seen from a complexity theoretic perspective, the universe is not an exponential place. A fact that disallows such a derivation is the existence of…

Quantum Physics · Physics 2009-06-16 R. Srikanth

We introduce a new framework for contextuality based on simplicial sets, combinatorial models of topological spaces that play a prominent role in modern homotopy theory. Our approach extends measurement scenarios to consist of spaces…

Quantum Physics · Physics 2023-05-24 Cihan Okay , Aziz Kharoof , Selman Ipek

Models in which the space-time metric $g_{\mu\nu}$ is not symmetric, $i.e.$ $g_{\mu\nu} \ne g_{\nu\mu}$ may make predictions in scattering experiments, for example in a future $e^+e^-$ linear collider, similar to those from noncommutative…

High Energy Physics - Phenomenology · Physics 2007-05-23 N. Kersting , Y. L. Ma

Standard simple assumptions are usually made about the pre-Big Bang Nucleosynthesis epoch, from which we do not have observations. Modifying these assumptions, the predicted density of relic particles such as neutralinos and sterile…

High Energy Physics - Phenomenology · Physics 2008-05-14 Graciela B. Gelmini

Maxwell's equations are obeyed in a one-parameter group of isotropic gravity-free flat space-times whose metric depends upon the value of the group parameter. An experimental determination of this value has been proposed. If it is zero, the…

General Physics · Physics 2014-06-13 Carl E. Wulfman

We study a class of inhomogeneous and anisotropic $G_2$ string cosmological models. In the case of separable $G_2$ models we show that the governing equations reduce to a system of ordinary differential equations. We focus on a class of…

High Energy Physics - Theory · Physics 2014-11-18 Alan A. Coley , R. J. van den Hoogen

We analyze the structure of the so called non-signaling theories respecting relativistic causality but allowing correlations violating bounds imposed by quantum mechanics such as CHSH inequality. We discuss relations among such theories,…

Quantum Physics · Physics 2016-04-08 Tomasz Ignacy Tylec , Marek Kuś

We derive criteria for whether two cosmological events can have a shared causal past or a shared causal future, assuming a Friedmann-Lemaitre-Robertson-Walker universe with best-fit \Lambda CDM cosmological parameters from the Planck…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-30 Andrew S. Friedman , David I. Kaiser , Jason Gallicchio

Non-commutative spacetime and quantum groups have been argued to capture non-classical features of spacetime and its symmetries in the low-energy limit of quantum gravity. In this letter, we show that employing the $SU_q(2)$ quantum group…

Quantum Physics · Physics 2026-05-29 Vittorio D'Esposito , Giuseppe Fabiano , Domenico Frattulillo