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Related papers: The structure of cosmic time

200 papers

The notion of time in cosmology is revealed through an examination of transition matrix elements of radiative processes occurring in the cosmos. To begin with, the very concept of time is delineated in classical physics in terms of…

General Relativity and Quantum Cosmology · Physics 2009-10-30 R. Brout , R. Parentani

Time is a parameter playing a central role in our most fundamental modelling of natural laws. Relativity theory shows that the comparison of times measured by different clocks depends on their relative motion and on the strength of the…

General Relativity and Quantum Cosmology · Physics 2017-07-25 Hauret Clementine , Magain Pierre , Biernaux Judith

In this manuscript we initiate a systematic examination of the physical basis for the time concept in cosmology. We discuss and defend the idea that the physical basis of the time concept is necessarily related to physical processes which…

General Relativity and Quantum Cosmology · Physics 2009-02-23 Svend Erik Rugh , Henrik Zinkernagel

We propose that cosmological time is {\it effectively} the conjugate of the constants of nature. Different definitions of time arise, with the most relevant related to the constant controlling the dynamics in each epoch. The Hamiltonian…

General Relativity and Quantum Cosmology · Physics 2021-06-30 Joao Magueijo

Time is a parameter playing a central role in our most fundamental modeling of natural laws. Relativity theory shows that the comparison of times measured by different clocks depends on their relative motions and on the strength of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-11 Pierre Magain , Clémentine Hauret

Time has always played a crucial role in cosmology. I review some of the aspects of the present cosmological model which are more directly related to time, such as: the definition of a cosmic time; the existence of typical timescales and…

History and Philosophy of Physics · Physics 2017-03-22 A. Balbi

Astronomical observations strongly suggest that our universe is now accelerating and contains a substantial admixture of dark vacuum energy. Using numerical simulations to study this newly consolidated cosmological model (with a constant…

Astrophysics · Physics 2009-11-10 Fred C. Adams , Michael T. Busha , August E. Evrard , Risa H. Wechsler

The nature of cosmic time is illuminated using Hamilton-Jacobi theory for general relativity. For problems of interest to cosmology, one may solve for the phase of the wavefunctional by using a line integral in superspace. Each contour of…

Astrophysics · Physics 2009-10-28 D. S. Salopek

Astrophysical observations provide a picture of the universe as a 4-dim homogeneous and isotropic flat space-time dominated by an unknown form of dark energy. To achieve such a cosmology one has to consider in the early universe an…

Astrophysics · Physics 2009-11-10 F. Canfora , A. Troisi

A regular (i.e., singularity-free) cycling cosmological model is advanced. In the model, there are only two constants: the gravitational constant (or the Planck time) and the cosmic period. The radius of the universe is a simple periodic…

General Physics · Physics 2011-12-30 Vladimir S. Mashkevich

In this paper we discuss a possible cosmological time evolution of fundamental constants from the theoretical and experimental point of views. On the theoretical side, we explain that such a cosmological time evolution is actually something…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Xavier Calmet , Matthias Keller

In a previous effort [arXiv:1708.05492] we have created a framework that explains why topological structures naturally arise within a scientific theory; namely, they capture the requirements of experimental verification. This is…

General Physics · Physics 2020-06-25 Gabriele Carcassi , Christine A. Aidala

In this work, we compute the universe temperature for the cosmological horizon for the FLRW metric. For this purpose, we consider a scalar field on the cosmological horizon. This scalar field satisfies the Klein-Gordon equation in a curved…

General Relativity and Quantum Cosmology · Physics 2024-05-15 Armando Meza Gaxiola , Pablo Padilla Longoria

We investigate the cosmological behavior in a universe governed by time asymmetric extensions of general relativity, which is a novel modified gravity based on the addition of new, time-asymmetric, terms on the Hamiltonian framework, in a…

General Relativity and Quantum Cosmology · Physics 2015-11-11 Genly Leon , Emmanuel N. Saridakis

Time is a parameter playing a central role in our most fundamental modelling of natural laws. Relativity theory shows that the comparison of times measured by different clocks depends on their relative motions and on the strength of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-05 Pierre Magain , Clémentine Hauret

A unique feature of gravity is its ability to control the information accessible to any specific observer. We quantify the notion of cosmic information ('CosmIn') for an eternal observer in the universe. Demanding the finiteness of CosmIn…

General Relativity and Quantum Cosmology · Physics 2017-08-28 T. Padmanabhan , Hamsa Padmanabhan

Observations indicate that the evolution of our universe can be divided into three epochs consisting of early time inflation, radiation (and matter) domination and the late time acceleration. One can associate with each of these epochs a…

High Energy Physics - Theory · Physics 2012-10-17 T. Padmanabhan

We use the phase plane analysis technique of Madsen and Ellis to consider a universe with a true cosmological constant as well as a cosmological "constant" that is decaying. Time symmetric dynamics for the inflationary era allows eternally…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-27 George F. R. Ellis , Emma Platts , David Sloan , Amanda Weltman

In this paper we build on our previous work and the work of Peter Lynds within a Bohmian framework to consider the intervallic structure of thermodynamic reversibility as well as presenting new considerations for the measurement of…

General Physics · Physics 2011-05-10 Maurice Passman , Philip V. Fellman , Jonathan Vos Post

It is a remarkable fact that all processes occurring in the observable Universe are irreversible, whereas the equations through which the fundamental laws of physics are formulated are invariant under time reversal. The emergence of…

General Physics · Physics 2015-05-28 Gustavo E. Romero , Daniela Pérez
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