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Related papers: Effects of Cosmic Strings on Free Streaming

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We describe the detailed study and results of high-resolution numerical simulations of string-induced structure formation in open universes and those with a non-zero cosmological constant. The effect from small loops generated from the…

Astrophysics · Physics 2009-09-25 J. H. P. Wu , P. P. Avelino , E. P. S. Shellard , B. Allen

The cosmic string scenario in an open universe is developed -- including the equations of motion, a model of network evolution, the large angular scale CMB temperature anisotropy, and the power spectrum of density fluctuations produced by…

Astrophysics · Physics 2009-10-30 P. P. Avelino , R. R. Caldwell , C. J. A. P. Martins

Cosmic strings are topological defects possibly formed in the early Universe, which may be observable due to their gravitational effects on the cosmic microwave background radiation or gravitational wave experiments. To this effect it is…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-01 R. P. L. Azevedo , C. J. A. P. Martins

Wave or fuzzy dark matter that is produced with relativistic wavenumbers exhibits free streaming effects analogous to warm or hot particle dark matter with relativistic momenta. Axions produced after inflation provide such a warm or mildly…

High Energy Physics - Phenomenology · Physics 2025-09-11 Rayne Liu , Wayne Hu , Huangyu Xiao

We examine variations in the equation of state of the cosmic string portion of the cosmological fluid which lead to perturbations of the background matter density. These fluctuations in the equation of state are due to variations in the…

Astrophysics · Physics 2010-01-06 Pedro Avelino , Robert Caldwell

We study the evolution of cosmic strings taking into account the frictional force due to the surrounding radiation. We consider small perturbations on straight strings, oscillation of circular loops and small perturbations on circular…

High Energy Physics - Theory · Physics 2009-10-22 J. Garriga , M. Sakellariadou

The dynamics of cosmic strings is considered in anisotropic backgrounds. In particular, the behaviour of infinitely long straight cosmic strings and of cosmic string loops is determined. Small perturbations of a straight cosmic string are…

High Energy Physics - Theory · Physics 2012-04-25 Kerstin E. Kunze , Mairi Sakellariadou

Cosmic string networks generate cosmological perturbations actively throughout the history of the universe. Thus, the string sourced anisotropy of the cosmic microwave background is not affected by Silk damping as much as the anisotropy…

Astrophysics · Physics 2010-04-15 Levon Pogosian , S. -H. Henry Tye , Ira Wasserman , Mark Wyman

We describe the results of high-resolution numerical simulations of string-induced structure formation in open universes and those with a non-zero cosmological constant. For models with $\Gamma = \Omega h = 0.1 - 0.2$ and a cold dark matter…

Astrophysics · Physics 2008-11-26 P. P. Avelino , E. P. S. Shellard , J. H. P. Wu , B. Allen

The cosmic string theory for cosmological fluctuations is a good example of healthy scientific progress in cosmology. It is a well defined physically motivated model that has been tested by cosmological observations and has been ruled out…

Astrophysics · Physics 2009-11-10 L. Perivolaropoulos

We calculate the fluctuations in the current and energy densities for the case of a quantized, minimally coupled, massless, complex scalar field around a straight and infinitesimally thin cosmic string carrying magnetic flux. At zero…

General Relativity and Quantum Cosmology · Physics 2009-10-31 L. Sriramkumar

We study the behaviour of cosmic string networks in contracting universes, and discuss some of their possible consequences. We note that there is a fundamental time asymmetry between defect network evolution for an expanding universe and a…

Astrophysics · Physics 2009-11-07 P. P. Avelino , C. J. A. P. Martins , C. Santos , E. P. S. Shellard

Cosmic (super)strings offer promising ways to test ideas about the early universe and physics at high energies. While in field theory constructions their tension is usually assumed to be constant (or at most slowly-varying), this is often…

High Energy Physics - Phenomenology · Physics 2025-05-08 Filippo Revello , Gonzalo Villa

Quantum fluctuations created during inflation can account for the observed matter distribution in the linear regime if the universe has two components of dark matter, one which is cold and collisionless, and the other which is hot and free…

Astrophysics · Physics 2007-05-23 Richard A. Battye , Joao Magueijo , Jochen Weller

We show that adiabatic, super-Hubble, and almost scale invariant density fluctuations are produced by cosmic strings in a contracting universe. An essential point is that isocurvature perturbations produced by topological defects such as…

Astrophysics · Physics 2009-07-22 Robert H. Brandenberger , Tomo Takahashi , Masahide Yamaguchi

We investigate cosmological evolution and implications of cosmic strings with time-dependent tension. We derive basic equations of time development of the correlation length and the velocity of such strings, based on the one scale model.…

High Energy Physics - Phenomenology · Physics 2008-11-26 Kazuhide Ichikawa , Tomo Takahashi , Masahide Yamaguchi

We study the effects of cosmic strings on structure formation in open universes. We calculate the power spectrum of density perturbations for two class of models: one in which all the dark matter is non baryonic (CDM) and one in which it is…

Astrophysics · Physics 2009-10-22 Pedro Ferreira

Appearance of cosmic strings in the early Universe is a common manifestation of new physics typically linked to some high energy scale. In this paper, we discuss a different situation, where a model underlying cosmic string formation is…

High Energy Physics - Phenomenology · Physics 2022-02-02 William T. Emond , Sabir Ramazanov , Rome Samanta

We study the distribution of dark matter in the nonlinear regime in a model in which the primordial fluctuations include, in addition to the dominant primordial Gaussian fluctuations generated by the standard $\Lambda CDM$ cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-24 Disrael Cunha , Joachim Harnois-Deraps , Robert Brandenberger , Adam Amara , Alexandre Refregier

Cosmic strings provide a radically different paradigm for the formation of structure to the prevailing inflationary one. They afford some extra technical complications: for example, the calculation of the power spectrum of matter and…

Astrophysics · Physics 2007-05-23 Mark Hindmarsh , Mairi Sakellariadou , Graham R. Vincent
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