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We apply the Effective Field Theory of Large-Scale Structure (EFTofLSS) to analyze cosmological models with clustering quintessence, which allows us to consistently describe the parameter region in which the quintessence equation of state…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-31 Guido D'Amico , Yaniv Donath , Leonardo Senatore , Pierre Zhang

We study effect of superhorizon tensor perturbations on scalar perturbations, so called effect of clustering fossils, in cosmological model in which inflation is driven by both solid matter and scalar field. The effect deforms primordial…

General Relativity and Quantum Cosmology · Physics 2019-09-25 Peter Mészáros

The evolution of marginally bound supercluster-like objects in an accelerating LambdaCDM Universe is followed, by means of cosmological simulations, from the present time to an expansion factor a = 100. The objects are identified on the…

We study the most general cosmological model with real scalar field which is minimally coupled to gravity. Our calculations are based on Friedmann-Lemaitre-Robertson-Walker (FLRW) background metric. Field equations consist of three…

General Relativity and Quantum Cosmology · Physics 2023-03-22 Medine Ildes , Metin Arik

Local measurements of the Hubble expansion rate are affected by structures like galaxy clusters or voids. Here we present a fully relativistic treatment of this effect, studying how clustering modifies the mean distance (modulus)-redshift…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-10 Ido Ben-Dayan , Ruth Durrer , Giovanni Marozzi , Dominik J. Schwarz

We discuss the phenomenological model in which the potential energy of the quintessence field depends linearly on the energy density of the spatial curvature. We find that the pressure of the scalar field takes a different form when the…

High Energy Physics - Theory · Physics 2014-11-18 Yungui Gong , Anzhong Wang , Yuan-Zhong Zhang

We investigate the effects of chameleon scalar field to the effective density and pressure of a dark matter halo. The pressure is generated from the chameleonic fifth force on the matter. We demonstrate that the thick-shell non-singular…

High Energy Physics - Phenomenology · Physics 2012-08-31 Piyabut Burikham , Sirachak Panpanich

Neutrinos interacting with the quintessence field can trigger the accelerated expansion of the Universe. In such models with a growing neutrino mass the homogeneous cosmological solution is often unstable to perturbations. We present…

Astrophysics · Physics 2008-11-26 N. Brouzakis , N. Tetradis , C. Wetterich

The problem of the cosmic coincidence is a longstanding puzzle. This conundrum may be solved by introducing a coupling between the two dark sectors. In this Letter, we study two cases of the coupled quintessence scenario. $(a)$ Assume that…

Astrophysics · Physics 2009-11-10 Xin Zhang

We compute the circuit complexity of scalar curvature perturbations on FLRW cosmological backgrounds with fixed equation of state $w$ using the language of squeezed vacuum states. Backgrounds that are accelerating and expanding, or…

High Energy Physics - Theory · Physics 2020-08-24 Arpan Bhattacharyya , Saurya Das , S. Shajidul Haque , Bret Underwood

We present a new model for the formation of spherically symmetric clusters in an expanding Universe. Both the Universe and the collapsing cluster are governed by the same pressure less fluid equations for which a uniform initial density…

Astrophysics · Physics 2007-05-23 Y. Dabrowski , M. P. Hobson , A. N. Lasenby , C. Doran

A generic feature of cosmic quintessence models is the possibility of significant energy density in the scalar field during the radiation dominated epoch. This possibility is even greater if the quintessence field begins in a…

Astrophysics · Physics 2007-05-23 G. J. Mathews , K. Ichiki , T. Kajino , M. Orito , M. Yahiro

The nonminimal coupling (NMC) of the scalar field to the Ricci curvature is unavoidable in many cosmological scenarios. Inflation and quintessence models based on nonminimally coupled scalar fields are studied, with particular attention to…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Valerio Faraoni

In an undulant universe, cosmic expansion is characterized by alternating periods of acceleration and deceleration. We examine cosmologies in which the dark-energy equation of state varies periodically with the number of e-foldings of the…

Astrophysics · Physics 2009-11-11 Gabriela Barenboim , Olga Mena Requejo , Chris Quigg

Over the coming decade, the observational samples available for studies of cluster abundance evolution will increase from tens to hundreds, or possibly to thousands, of clusters. Here we assess the power of future surveys to determine…

Astrophysics · Physics 2009-11-06 Zoltan Haiman , Joseph J. Mohr , Gilbert P. Holder

We use cosmological perturbation theory to study the backreaction effects of a self-consistent and well-defined cosmological averaging on the dynamics and the evolution of the Universe. Working with a perturbed…

General Relativity and Quantum Cosmology · Physics 2013-10-30 Iain A. Brown , Alan A. Coley , D. Leigh Herman , Joey Latta

We present a realistic scenario of tracking of scalar fields with varying equation of state. The astrophysical constraints on the evolution of scalar fields in the physical universe are discussed. The nucleosynthesis and the galaxy…

Astrophysics · Physics 2011-07-19 Vinod B. Johri

In a recent publication, we have discussed the effects of boundary conditions in finite quantum systems and their connection with symmetries. Focusing on the one-dimensional Hubbard Hamiltonian under twisted boundary conditions, we have…

Strongly Correlated Electrons · Physics 2018-08-01 Krissia Zawadzki , Irene D'Amico , Luiz N. Oliveira

The accelerated expansion of the universe is a rather established fact in cosmology and many different models have been proposed as a viable explanation. Many of these models are based on the standard general relativistic framework of…

General Relativity and Quantum Cosmology · Physics 2016-05-20 N. Nazari-Pooya , M. Malekjani , F. Pace , D. Mohammad-Zadeh Jassur

The evidence for the accelerated expansion of the universe and the time-dependence of the fine-structure constant suggests the existence of at least one scalar field with a mass of order H_0. If such a field exists, then it is generally…

Astrophysics · Physics 2009-11-10 Justin Khoury , Amanda Weltman