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We compile an updated list of 38 measurements of the Hubble parameter $H(z)$ between redshifts $0.07 \leq z \leq 2.36$ and use them to place constraints on model parameters of constant and time-varying dark energy cosmological models, both…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 Omer Farooq , Foram Madiyar , Sara Crandall , Bharat Ratra

In this paper a new approach to investigation of Quantum and Statistical Mechanics of the Early Universe (Planck scale) - density matrix deformation - is proposed. The deformation is understood as an extension of a particular theory by…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Alex E. Shalyt-Margolin

We have performed the dynamical system analysis to obtain the critical point in which, the value of the geometric and dynamical parameters satisfy the late-time cosmic behavior of the Universe. At the outset, the modified Friedmann…

General Relativity and Quantum Cosmology · Physics 2025-10-30 Rahul Bhagat , B. Mishra

The macroscopic behavior of dense suspensions of neutrally-buoyant spheres in turbulent plane channel flow is examined. We show that particles larger than the smallest turbulence scales cause the suspension to deviate from the continuum…

Fluid Dynamics · Physics 2016-09-28 Pedro Costa , Francesco Picano , Luca Brandt , Wim-Paul Breugem

(context) Different cosmological data are consistent with an accelerated expansion produced by an exotic matter-energy component, dubbed "dark-energy''. A cosmological constant is a possibility since it satisfies most of the observational…

Astrophysics · Physics 2010-01-15 Sébastien Peirani , José Antonio De Freitas Pacheco

Nonlinear perturbations of Friedmann-Lemaitre cosmologies with dust and a positive cosmological constant have recently attracted considerable attention. In this paper our first goal is to compare the evolution of the first and second order…

General Relativity and Quantum Cosmology · Physics 2013-08-28 Claes Uggla , John Wainwright

A large bulk flow, which is in tension with the Lambda Cold Dark Matter ($\Lambda$CDM) cosmological model, has been observed. In this paper, we provide a physically plausible explanation of this bulk flow, based on the assumption that some…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-19 Yin-Zhe Ma , Christopher Gordon , Hume A. Feldman

We study stationary fluctuations of conserved slow modes in a two-lane model of hardcore particles which are expected to show universal behaviour. Specifically, we focus on the properties of fluctuations at a special umbilic point where the…

Statistical Mechanics · Physics 2025-09-08 Johannes Schmidt , Žiga Krajnik , Vladislav Popkov

We elaborate on the principle that for gapped quantum spin systems with local interaction "local perturbations [in the Hamiltonian] perturb locally [the ground state]". This principle was established in [Bachmann et al. 2012], relying on…

Mathematical Physics · Physics 2015-06-30 Wojciech De Roeck , Marius Schütz

We study the momentum-space entanglement between the sub- and super-Hubble modes of a spectator scalar field, with a cubic $\lambda \phi^3$ interaction, in de Sitter space. Momentum-space entanglement has some universal properties for any…

High Energy Physics - Theory · Physics 2023-02-28 Suddhasattwa Brahma , Jaime Calderón-Figueroa , Moatasem Hassan , Xuan Mi

This review is intended to give a pedagogical and unified view on the subject of the statistics and scaling of physical quantities in disordered electron systems at very low temperatures. Quantum coherence at low temperatures and randomness…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 Martin Janssen

In this work a new law of varying deceleration parameter of third degree have been proposed. The solutions of the modified field equations have been derived under the newly proposed law of the deceleration parameter. Model exhibits the…

General Relativity and Quantum Cosmology · Physics 2022-08-23 Leishingam Kumrah , S. Surendra Singh , L. Anjana Devi , Md Khurshid Alam

Some general remarks are made about the quantum theory of scalar fields and the definition of momentum in curved space. Special emphasis is given to field theory in anti-de Sitter space, as it represents a maximally symmetric space-time of…

High Energy Physics - Theory · Physics 2008-02-03 Simon Davis

Standard treatments of general relativity accept the gravitational slowing of clocks as a primary phenomenon, requiring no further analysis as to cause. Rejecting this attitude, I argue that one or more of the fundamental "constants"…

General Relativity and Quantum Cosmology · Physics 2007-05-23 John E. Heighway

In this paper, we have proposed a generalized parametrization for the deceleration parameter $q$ in order to study the evolutionary history of the universe. We have shown that the proposed model can reproduce three well known…

General Relativity and Quantum Cosmology · Physics 2018-04-25 Abdulla Al Mamon

Friedmann-Lemaitre universes driven by a scalar field, spatially closed and bouncing, were recently studied by Martin and Peter in [1], with the conclusion that the spectrum of their large scale matter perturbations was generically modified…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Nathalie Deruelle

We investigate the effects of a special kind of dynamical deformation between the momenta of the scalar field of the Brans-Dicke theory and the scale factor of the FRW metric. This special choice of deformation includes linearly a…

General Relativity and Quantum Cosmology · Physics 2011-09-28 S. M. M. Rasouli , Mehrdad Farhoudi , Nima Khosravi

Assuming only a homogeneous and isotropic universe and using both the 'Gold' Supernova Type Ia sample of Riess et al. and the results from the Supernova Legacy Survey, we calculate the Bayesian evidence of a range of different…

Astrophysics · Physics 2011-01-20 Oystein Elgaroy , Tuomas Multamaki

In the early seventies, Alan Sandage defined cosmology as the search for two numbers: Hubble parameter ${{H}_{0}}$ and deceleration parameter ${{q}_{0}}$. The first of the two basic cosmological parameters (the Hubble parameter) describes…

General Relativity and Quantum Cosmology · Physics 2015-02-04 Yu. L. Bolotin , V. A. Cherkaskiy , O. A. Lemets , D. A. Yerokhin , L. G. Zazunov

A local void in the globally Friedmann-Robertson-Walker cosmological model with the critical density ($\Omega_{0}=1$) is studied. The inhomogeneity is described using a Lema\^{\i}tre-Tolman-Bondi solution for a spherically symmetric…

Astrophysics · Physics 2008-02-03 J. W. Moffat , D. C. Tatarski