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Related papers: Wiggly cosmic strings accrete dark energy

200 papers

We present concrete solutions with accelerated expansion in string theory, requiring a small, tractable list of stress energy sources. We explain how this construction (and others in progress) evades previous no go theorems for simple…

High Energy Physics - Theory · Physics 2014-12-09 Matthew Dodelson , Xi Dong , Eva Silverstein , Gonzalo Torroba

In this Letter, we study the implications of string Swampland criteria for dark energy in view of ongoing and future cosmological observations. If string theory should be the ultimate quantum gravity theory, there is evidence that exact de…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-12 Lavinia Heisenberg , Matthias Bartelmann , Robert Brandenberger , Alexandre Refregier

Dark energy, the main constituent in our expanding universe, responsible for its acceleration, is currently being observed with unprecedented precision through various experiments. While several cosmological models can fit this latest data,…

High Energy Physics - Theory · Physics 2026-04-10 David Andriot

Faced by recent evidence for a flat universe dominated by dark energy, cosmologists grapple with deep cosmic enigmas such as the cosmological constant problem, extreme fine-tuning and the cosmic coincidence problem. The extent to which we…

Astrophysics · Physics 2016-08-30 Greg Huey , Benjamin D. Wandelt

Accretion of dark energy onto black holes will take place when dark energy is not a cosmological constant. It has been proposed that the time evolution of the mass of the black holes in binary systems due to dark energy accretion could be…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Jonas Enander , Edvard Mortsell

We study perturbations of black holes absorbing dark energy. Due to the accretion of dark energy, the black hole mass changes. We observe distinct perturbation behaviors for absorption of different forms of dark energy into the black holes.…

General Relativity and Quantum Cosmology · Physics 2009-03-19 Xi He , Bin Wang , Shao-Feng Wu , Chi-Yong Lin

We explore the properties of dark energy models for which the equation-of-state, w, defined as the ratio of pressure to energy density, crosses the cosmological-constant boundary w = -1. We adopt an empirical approach, treating the dark…

Astrophysics · Physics 2010-04-06 Robert R. Caldwell , Michael Doran

Pixelated dark energy is a string theory scenario with a quantum mechanically stable cosmological constant. The number of pixels that make up the universe slowly increases, manifesting as a time-dependent source of dark energy. DESI has…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-16 Jonathan J. Heckman , Omar F. Ramadan , Jeremy Sakstein

A string field theory(SFT) nonlocal model of the cosmological dark energy providing w<-1 is briefly surveyed. We summarize recent developments and open problems, as well as point out some theoretical issues related with others applications…

High Energy Physics - Theory · Physics 2008-11-26 Irina Ya. Aref'eva

It has recently been argued that string theory does not admit de Sitter vacua. This would imply that the current accelerated expansion of the universe is not driven by a cosmological constant (or vacuum energy) but by other means such as a…

High Energy Physics - Theory · Physics 2019-07-24 Carsten van de Bruck , Cameron C. Thomas

We construct several new families of vacuum solutions that describe black holes in uniformly accelerated motion. They generalize the C-metric to the case where the energy density and tension of the strings that pull (or push) on the black…

General Relativity and Quantum Cosmology · Physics 2015-03-17 Joan Camps , Roberto Emparan

We study the phenomenology of a recent string construction with a quantum mechanically stable dark energy. A mild supersymmetry protects the vacuum energy but also allows $O(10 - 100)$ TeV scale superpartner masses. The construction is…

High Energy Physics - Theory · Physics 2020-01-08 Jonathan J. Heckman , Craig Lawrie , Ling Lin , Jeremy Sakstein , Gianluca Zoccarato

We examine cyclic phantom models for the universe, in which the universe is dominated sequentially by radiation, matter, and a phantom dark energy field, followed by a standard inflationary phase. Since this cycle repeats endlessly, the…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Hui-Yiing Chang , Robert J. Scherrer

We show that the latest empirical constraints on cosmology, from a combination of DESI, CMB and supernova data, can be accounted for if a small component of dark matter has an evolving and oscillating equation of state within $-1<w<1$. From…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-22 Xingang Chen , Abraham Loeb

We present results of a cosmological hydrodynamical study of gravitational accretion in cosmic string wakes and filaments. Cosmic string wakes are formed by fast moving (v ~ c) strings. A conical deficit angle in the string spacetime…

Astrophysics · Physics 2007-05-23 A. Sornborger , R. Brandenberger , B. Fryxell , K. Olson

The role of anisotropic components on the dark energy and the dynamics of the universe is investigated. An anisotropic dark energy fluid with different pressures along different spatial directions is assumed to incorporate the effect of…

General Physics · Physics 2018-04-16 B. Mishra , S. K. Tripathy , Pratik P Ray

One of the main virtues of string gas cosmology is that it resolves cosmological singularities. Since the Universe can be approximated by a locally asymptotically de Sitter spacetime by the end of the inflationary era, a singularity theorem…

High Energy Physics - Theory · Physics 2010-12-23 Brett McInnes

We rederive the equations of motion for relativistic strings, that is, one-dimensional elastic bodies whose internal energy depends only on their stretching, and use them to study circular string loops rotating in the equatorial plane of…

General Relativity and Quantum Cosmology · Physics 2023-10-12 Jose Natario , Leonel Queimada , Rodrigo Vicente

We study the accretion of cold and hot dark matter onto a cosmic string wake using a high-resolution numerical simulation. We verify previous analytical calculations predicting the radius of bound matter around wakes and inflow velocities…

Astrophysics · Physics 2016-08-25 Andrew T. Sornborger

We make use of the formalism described in a previous paper [Martins {\it et al.} Phys. Rev. D90 (2014) 043518] to address general features of wiggly cosmic string evolution. In particular, we highlight the important role played by poorly…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-21 J. P. P. Vieira , C. J. A. P. Martins , E. P. S. Shellard