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Related papers: Limits of time in cosmology

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We investigate the effects of Quantum Gravity on the Planck era of the universe. In particular, using different versions of the Generalized Uncertainty Principle and under specific conditions we find that the main Planck quantities such as…

High Energy Physics - Theory · Physics 2010-09-28 Spyros Basilakos , Saurya Das , Elias C. Vagenas

We propose that physical time is based on counting the oscillations of wave functions. The discrete counting of the ticks of these clocks does not depend on the metric frame. It remains well defined for the beginning epochs of the universe.…

General Relativity and Quantum Cosmology · Physics 2024-08-06 Christof Wetterich

We show that (in contrast to a rather common opinion) QM is not a complete theory. This is a statistical approximation of classical statistical mechanics on the {\it infinite dimensional phase space.} Such an approximation is based on the…

High Energy Physics - Theory · Physics 2009-11-11 Andrei Khrennikov

We consider what the implications would be if there were a discrete fundamental model of physics based on locally-finite self-interacting information, in which there is no presumption of the familiar space and laws of physics, but from…

General Relativity and Quantum Cosmology · Physics 2011-11-10 Dirk Vertigan

Many extensions of the Standard Model predict large numbers of additional unstable particles whose decays in the early universe are tightly constrained by observational data. For example, the decays of such particles can alter the ratios of…

High Energy Physics - Phenomenology · Physics 2019-02-20 Keith R. Dienes , Jason Kumar , Patrick Stengel , Brooks Thomas

Limits are imposed upon the possible rate of change of extra spatial dimensions in a decrumpling model Universe with time variable spatial dimensions (TVSD) by considering the time variation of (1+3)-dimensional Newton's constant. Previous…

High Energy Physics - Theory · Physics 2009-11-10 Forough Nasseri

A precise measurement of the curvature of the Universe is of primeval importance for cosmology since it could not only confirm the paradigm of primordial inflation but also help in discriminating between different early Universe scenarios.…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-27 Eleonora Di Valentino , Luis A. Anchordoqui , Ozgur Akarsu , Yacine Ali-Haimoud , Luca Amendola , Nikki Arendse , Marika Asgari , Mario Ballardini , Spyros Basilakos , Elia Battistelli , Micol Benetti , Simon Birrer , François R. Bouchet , Marco Bruni , Erminia Calabrese , David Camarena , Salvatore Capozziello , Angela Chen , Jens Chluba , Anton Chudaykin , Eoin Ó Colgáin , Francis-Yan Cyr-Racine , Paolo de Bernardis , Javier de Cruz Pérez , Jacques Delabrouille , Celia Escamilla-Rivera , Agnès Ferté , Fabio Finelli , Wendy Freedman , Noemi Frusciante , Elena Giusarma , Adrià Gómez-Valent , Will Handley , Ian Harrison , Luke Hart , Alan Heavens , Hendrik Hildebrandt , Daniel Holz , Dragan Huterer , Mikhail M. Ivanov , Shahab Joudaki , Marc Kamionkowski , Tanvi Karwal , Lloyd Knox , Suresh Kumar , Luca Lamagna , Julien Lesgourgues , Matteo Lucca , Valerio Marra , Silvia Masi , Sabino Matarrese , Arindam Mazumdar , Alessandro Melchiorri , Olga Mena , Laura Mersini-Houghton , Vivian Miranda , Cristian Moreno-Pulido , David F. Mota , Jessica Muir , Ankan Mukherjee , Florian Niedermann , Alessio Notari , Rafael C. Nunes , Francesco Pace , Andronikos Paliathanasis , Antonella Palmese , Supriya Pan , Daniela Paoletti , Valeria Pettorino , Francesco Piacentini , Vivian Poulin , Marco Raveri , Adam G. Riess , Vincenzo Salzano , Emmanuel N. Saridakis , Anjan A. Sen , Arman Shafieloo , Anowar J. Shajib , Joseph Silk , Alessandra Silvestri , Martin S. Sloth , Tristan L. Smith , Joan Solà , Carsten van de Bruck , Licia Verde , Luca Visinelli , Benjamin D. Wandelt , Deng Wang , Jian-Min Wang , Anil K. Yadav , Weiqiang Yang

An extrinsic time is identified in most isotropic and homogeneous cosmological models by matching them with the ideal clock - a parametrized system whose only "degree of freedom" is time -. Once this matching is established, the…

General Relativity and Quantum Cosmology · Physics 2009-10-22 S. C. Beluardi , Rafael Ferraro

We consider cosmological scenarios in which density perturbations are generated by the quantum fluctuations of the inflaton field at early times; the late time dynamics involves a modulus which first dominates the energy density of the…

High Energy Physics - Phenomenology · Physics 2015-03-09 Koushik Dutta , Anshuman Maharana

The consideration of dark energy's quanta, required also by thermodynamics, introduces its chemical potential into the cosmological equations. Isolating its main contribution, we obtain solutions with dark energy decaying to matter or…

Astrophysics · Physics 2007-05-23 J. Besprosvany

This is a short summary of a project to construct a first principles cosmology of the Standard Model epoch, the period starting shortly before the electro-weak transition. The cosmology is derived from a simple initial state entirely within…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-14 Daniel Friedan

We discuss the asymmetry of cosmic background evolution in time with respect to the quantum bounce in the Loop Quantum Cosmology (LQC), employing the value of scalar field at the bounce $\phi_{\rm B}$. We use the Chaotic and the $R^2$…

General Relativity and Quantum Cosmology · Physics 2019-07-03 Wen-Hsuan Lucky Chang , Jiun-Huei Proty Wu

We present here the transformations required to recast the Robertson-Walker metric and Friedmann-Robertson-Walker equations in terms of observer-dependent coordinates for several commonly assumed cosmologies. The overriding motivation is…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-26 Fulvio Melia , Majd Abdelqader

Within a theory of the existing fundamental length on the order of Planck's a high-energy deformation of the General Relativity for the space with horizon has been constructed. On this basis, Markov's work of the early eighties of the last…

General Relativity and Quantum Cosmology · Physics 2015-05-27 A. E. Shalyt-Margolin

We provide a rationale for the Planck scale being the minimum scale in the universe, as also its specific numerical values. In the process we answer the question of why the Planck scale is $10^{20}$ times the Compton scale of elementary…

General Physics · Physics 2007-05-23 Burra G. Sidharth

We regard the background of space-time as a physical system composed of discrete volume elements at the Planck scale and get the internal energy of space-time by Debye model. A temperature-dependent minimum energy limit of the particles is…

General Relativity and Quantum Cosmology · Physics 2020-07-03 Qi-Qi Fan , Cong Li , Hao-Ran Zhang , Peng-Zhang He , Jian-Bo Deng

We present a novel test of the cosmological principle: the idea that, on sufficiently large scales, the universe should appear homogeneous and isotropic to observers comoving with the Hubble flow. This is a fundamental assumption in modern…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-19 Oliver T. Oayda , Geraint F. Lewis

We argue that in classical and quantum theories of gravity the configuration space and Hilbert space may not be constructible through any finite procedure. If this is the case then the "problem of time" in quantum cosmology may be a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Stuart Kauffman , Lee Smolin

The initial cosmological singularity in the framework of the general theory of relativity is resolved by introducing the effect of the uncertainty principle of quantum theory without violating conventional laws of physics. A plausible…

Astrophysics · Physics 2009-11-07 D. C. Choudhury

The problem of time of quantum gravity has been argued to make canonical approaches unsatisfactory. In this article I study how it affects quantum cosmology and reach the same conclusion. The advantage of studying the cosmological case is…

History and Philosophy of Physics · Physics 2026-03-11 Álvaro Mozota Frauca
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