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Related papers: Cosmic Necklaces from String Theory

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We present the first complete Markov chain Monte Carlo analysis of cosmological models with evolving cosmic (super)string networks, using the unconnected segment model in the unequal-time correlator formalism. For ordinary cosmic string…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-08 Tom Charnock , Anastasios Avgoustidis , Edmund J. Copeland , Adam Moss

As a most promising candidate for quantum theory of the gravity, the superstring theory has attracted many researchers including cosmologists. It is expected that the cosmological initial singularity is avoided within the context of the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Jiro Soda , Masa-aki Sakagami , Shinsuke Kawai

We develop velocity-dependent models describing the evolution of string networks that involve several types of interacting strings, each with a different tension. These incorporate the formation of Y-type junctions with links stretching…

Astrophysics · Physics 2014-11-18 A. Avgoustidis , E. P. S. Shellard

We show that cosmological observables can constrain the topology of the compact additional dimensions predicted by string theory. To do this, we develop a general strategy for relating cosmological observables to the microscopic parameters…

High Energy Physics - Theory · Physics 2008-11-26 Vijay Balasubramanian , Per Berglund , Raul Jimenez , Joan Simon , Licia Verde

Over the past three decades, considerable effort has been devoted to studying the rich and diverse phenomenologies of heterotic strings exhibiting spacetime supersymmetry. Unfortunately, during this same period, there has been relatively…

High Energy Physics - Theory · Physics 2015-07-01 Steven Abel , Keith R. Dienes , Eirini Mavroudi

Cosmic string networks are expected to form in early Universe phase transitions via the Kibble mechanism and are unavoidable in several Beyond the Standard Model theories. While most predictions of observational signals of string networks…

High Energy Physics - Phenomenology · Physics 2024-06-07 J. R. C. C. C. Correia , C. J. A. P. Martins , F. C. N. Q. Pimenta

We study the production of loops in the cosmic string network in the expanding background by means of a numerical simulation exact in the flat-spacetime limit and first-order in the expansion rate. We find an initial regime characterized by…

Astrophysics · Physics 2008-11-26 Ken D. Olum , Vitaly Vanchurin

Brane inflation in superstring theory predicts that cosmic strings (but not domain walls or monopoles) are produced towards the end of the inflationary epoch. Here, we discuss the production, the spectrum and the evolution of such cosmic…

High Energy Physics - Theory · Physics 2009-11-10 Nicholas T. Jones , Horace Stoica , S. -H. Henry Tye

We consider the effective action for strings and describe in detail the evolution of a four dimensional homogeneous isotropic universe with matter included. We find that the evolution, which is singular in general, becomes singularity free…

High Energy Physics - Theory · Physics 2009-10-30 S. Kalyana Rama

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

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

We investigate scaling and correlations of the energy and momentum in an evolving network of cosmic strings in Minkowski space. These quantities are of great interest, as they must be understood before accurate predictions for the power…

Astrophysics · Physics 2009-10-28 Graham R. Vincent , Mark Hindmarsh , Mairi Sakellariadou

We study the formation of three-string junctions between (p,q)-cosmic superstrings, and collisions between such strings and show that kinematic constraints analogous to those found previously for collisions of Nambu-Goto strings apply here…

High Energy Physics - Theory · Physics 2008-11-26 E. J. Copeland , H. Firouzjahi , T. W. B. Kibble , D. A. Steer

We consider grand unified theories with superconducting cosmic strings and which admit the mechanism for generating primordial magnetic fields recently discussed by Vachaspati. We show that these models are severely constrained by…

High Energy Physics - Phenomenology · Physics 2009-10-22 Robert H. Brandenberger , Anne-Christine Davis , Andrew M. Matheson , Mark Trodden

We consider new cosmological solutions with a collapsing, an intermediate and an expanding phase. The boundary between the expanding (collapsing) phase and the intermediate phase is seen by comoving observers as a cosmological past (future)…

High Energy Physics - Theory · Physics 2009-11-07 L. Cornalba , Miguel S. Costa

In supersymmetric theories, cosmic strings produced in the early Universe often have a width of TeV scale, while the tension is much larger. In a scaling regime, an infinite cosmic string releases significant fraction of its energy in the…

High Energy Physics - Phenomenology · Physics 2015-03-19 Masahiro Kawasaki , Koichi Miyamoto , Kazunori Nakayama

Cosmic strings are linear concentrations of energy that form whenever phase transitions in the early universe break axial symmetries as originally shown by Kibble. They are the result of frustrated order in the quantum fields responsible…

Astrophysics · Physics 2008-11-11 A. Achucarro , C. J. A. P. Martins

Local cosmic strings solutions are introduced in a model with a pseudo-anomalous U(1) gauge symmetry. Such a symmetry is present in many superstring compactification models. The coupling of those strings with the axion necessary in order to…

High Energy Physics - Phenomenology · Physics 2009-10-07 C. Deffayet

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

I report on recent numerical simulations of the simplest field theory with cosmic string solutions, the Abelian Higgs model. We find that random networks of string quickly converge to a scaling solution in which the network scale length…

High Energy Physics - Phenomenology · Physics 2016-10-26 Mark Hindmarsh
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