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Related papers: Fractional Cosmic String Loops In Expanding Univer…

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We study the evolution of simple cosmic string loop solutions in an inflationary universe. We show, for the particular case of circular loops, that periodic solutions do exist in a de Sitter universe, below a critical loop radius $R_c…

High Energy Physics - Phenomenology · Physics 2008-11-26 P. P. Avelino , C. J. A. P. Martins , E. P. S. Shellard

We investigate the evolution of infinite strings as a part of a complete cosmic string network in flat space. We perform a simulation of the network which uses functional forms for the string position and thus is exact to the limits of…

General Relativity and Quantum Cosmology · Physics 2013-05-29 Vitaly Vanchurin , Ken Olum , Alexander Vilenkin

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

We solve numerically the Boltzmann equation describing the evolution of a cosmic string network which contains only loops. In Minkowski space time the equilibrium solution predicted by statistical mechanics is recovered, and we prove that…

Astrophysics · Physics 2009-10-31 Joao Magueijo , Haavard Sandvik , Daniele Steer

Using recent simulation results, we provide the mass and speed spectrum of cosmic string loops. This is the quantity of primary interest for many phenomenological signatures of cosmic strings, and it can be accurately predicted using…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-22 Jose J. Blanco-Pillado , Ken D. Olum , Benjamin Shlaer

We study the spectrum of loops as a part of a complete network of cosmic strings in flat spacetime. After a long transient regime, characterized by production of small loops at the scale of the initial conditions, it appears that a true…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Vitaly Vanchurin , Ken D. Olum , Alexander Vilenkin

The velocity-dependent `one-scale' model of Martins and Shellard is used to study the evolution of a cosmic string network (and the corresponding loop population) in open universes. It is shown that in this case there is no linear scaling…

Astrophysics · Physics 2009-10-30 C. J. A. P. Martins

We examine the scaling properties of an evolving network of strings in Minkowski spacetime and study the evolution of length scales in terms of a 3-scale model proposed by Austin, Copeland and Kibble (ACK). We find good qualitative and some…

Astrophysics · Physics 2008-11-26 Graham R. Vincent , Mark Hindmarsh , Mairi Sakellariadou

Observational effects of cosmic string loops depend on how loops are distributed in space. Chernoff \cite{Chernoff} has argued that loops can be gravitationally captured in galaxies and that for sufficiently small values of $G\mu$ their…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-22 Mudit Jain , Alexander Vilenkin

In loop quantum cosmology, the values of volume fluctuations and correlations determine whether the dynamics of an evolving state exhibits a bounce. Of particular interest are states that are supported only on either the positive or the…

General Relativity and Quantum Cosmology · Physics 2020-01-06 Martin Bojowald

Highly nonlinear behavior of a system of discrete sites on a lattice is observed when a specific feedback loop is introduced into models employing coupled map lattices, quantum cellular automata, or the real-valued analogues of the latter.…

Adaptation and Self-Organizing Systems · Physics 2007-05-23 Siegfried Fussy , Gerhard Groessing , Herbert Schwabl

The equation governing the time evolution of the number density of loops in a cosmic string network is a detailed balance determined by energy conservation. We solve this equation with the inclusion of the gravitational radiation effect…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Jorge V. Rocha

This investigation is concerned with cosmological scenarios based on particle physics theories that give rise to superconducting cosmic strings (whose subsequent evolution may produce stable loop configurations known as vortons). Cases in…

High Energy Physics - Phenomenology · Physics 2009-10-31 B. Carter , R. Brandenberger , A. -C. Davis , G. Sigl

The standard cosmological model supposes that the dominant matter component changes in the course of the evolution of the universe. We study the homogeneous and isotropic universe with non-zero cosmological constant in the epoch when the…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-16 V. E. Kuzmichev , V. V. Kuzmichev

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

We study the cosmological evolution of a type-0 string theory by employing non-criticality, which may be induced by fluctuations of the D3 brane worlds. We check the consistency of the approach to O(alpha ') in the corresponding…

High Energy Physics - Theory · Physics 2009-11-07 G. A. Diamandis , B. C. Georgalas , N. E. Mavromatos , E. Papantonopoulos , I. Pappa

We consider the evolution of circular string loops in power law expanding universes represented by a spatially flat Friedman-Robertson-Walker metric with scale factor $a(t)\propto t^p$ where $t$ is the cosmic time and $p\geq 0$. Our main…

High Energy Physics - Theory · Physics 2009-10-22 A. L. Larsen , Minos Axenides

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

We consider F-strings with arbitrary configurations in the Minkowski directions of a higher-dimensional spacetime, which also wrap and spin around $S^1$ subcycles of constant radius in an arbitrary internal manifold, and determine the…

High Energy Physics - Phenomenology · Physics 2015-09-29 Daisuke Yamauchi , Matthew J. Lake

Progress on string theory in curved spacetimes since 1992 are reviewed. After a short introduction on strings in Minkowski and curved spacetimes, we focus on strings in cosmological spacetimes. The classical behaviour of strings in FRW and…

High Energy Physics - Theory · Physics 2009-09-25 H. J. de Vega , N. Sánchez