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Related papers: Scaling solutions for varying tension strings

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In the modified measure formulation the string tension appear as an additional dynamical degree of freedom and these tensions are not universal, but rather each string generates its own tension, which can have a different value for each…

High Energy Physics - Theory · Physics 2021-05-10 E. I. Guendelman

We study the cosmic microwave background temperature and polarisation spectra sourced by multi-tension cosmic superstring networks. First we obtain solutions for the characteristic length scales and velocities associated with the evolution…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Alkistis Pourtsidou , Anastasios Avgoustidis , Edmund J. Copeland , Levon Pogosian , Daniele A. Steer

Previously developed analytic models for the evolution of cosmic string and monopole networks are applied to networks of monopoles attached to two or more strings; the former case is usually known as cosmic necklaces. These networks are a…

High Energy Physics - Phenomenology · Physics 2014-11-21 C. J. A. P. Martins

We study the behaviour and consequences of cosmic string networks in contracting universes. They approximately behave during the collapse phase as a radiation fluids. Scaling solutions describing this are derived and tested against…

Astrophysics · Physics 2015-06-24 P. P. Avelino , C. J. A. P. Martins , C. Santos , E. P. S. Shellard

We obtain the equations of motion for cosmic strings in extensions of the 3+1 FRW model with extra dimensions. From these we derive a generalisation of the Velocity-dependent One-Scale (VOS) model for cosmic string network evolution which…

High Energy Physics - Phenomenology · Physics 2009-11-10 A. Avgoustidis , E. P. S. Shellard

Scaling behavior of scale-free evolving networks arising in communications, citations, collaborations, etc. areas is studied. We derive universal scaling relations describing properties of such networks and indicate limits of their…

Condensed Matter · Physics 2009-10-31 S. N. Dorogovtsev , J. F. F. Mendes

We investigate the effects of cosmological expansion on the spectrum of small-scale structure on a cosmic string. We simulate the evolution of a string with two modes that differ in wavelength by one order of magnitude. Once the short mode…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Christian Stephan-Otto , Ken D. Olum , Xavier Siemens

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

We study the evolution of non-interacting and entangled cosmic string networks in the context of the velocity-dependent one-scale model. Such networks may be formed in several contexts, including brane inflation. We show that the frozen…

High Energy Physics - Phenomenology · Physics 2009-11-10 C. J. A. P. Martins

The existence of a scaling evolution for cosmic string loops in an expanding universe is demonstrated for the first time by means of numerical simulations. In contrast with what is usually assumed, this result does not rely on any…

Astrophysics · Physics 2009-11-13 Christophe Ringeval , Mairi Sakellariadou , Francois Bouchet

The properties of string networks at scales well below the horizon are poorly understood, but they enter critically into many observables. We argue that in some regimes, stretching will be the only relevant process governing the evolution.…

High Energy Physics - Phenomenology · Physics 2008-11-26 Joseph Polchinski , Jorge V. Rocha

We extend and develop our previous work on the evolution of a network of cosmic strings. The new treatment is based on an analysis of the probability distribution of the end-to-end distance of a randomly chosen segment of left-moving string…

High Energy Physics - Phenomenology · Physics 2016-09-01 Daren Austin , E. J. Copeland , T. W. B. Kibble

The canonical velocity-dependent one-scale (VOS) model for cosmic string evolution contains a number of free parameters which cannot be obtained ab initio. Therefore it must be calibrated using high resolution numerical simulations. We…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-01 J. R. C. C. C. Correia , C. J. A. P. Martins

Cosmic strings with degrees of freedom beyond the standard Abrikosov-Nielsen-Olesen or Nambu-Goto strings are ubiquitous in field theory as well as in models with extra dimensions, such as string theoretic brane inflation scenarios. Here we…

High Energy Physics - Phenomenology · Physics 2015-06-03 M. F. Oliveira , A. Avgoustidis , C. J. A. P. Martins

We evolve the network of global strings in the matter-dominated universe by means of numerical simulations. The existence of the scaling solution is confirmed as in the radiation-dominated universe but the scaling parameter $\xi$ takes a…

High Energy Physics - Phenomenology · Physics 2009-12-30 Masahide Yamaguchi , Jun'ichi Yokoyama , M. Kawasaki

We revisit the cosmological evolution of domain wall networks, taking advantage of recent improvements in computing power. We carry out high-resolution field theory simulations in two, three and four spatial dimensions to study the effects…

High Energy Physics - Phenomenology · Physics 2015-05-30 A. M. M. Leite , C. J. A. P. Martins

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

Cosmic strings may have formed in the early universe due to the Kibble mechanism. While string networks are usually modeled as being of Nambu-Goto type, this description is understood to be a convenient approximation, which neglects the…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-01 A. R. R. Almeida , C. J. A. P. Martins

We found that models of evolving random networks exhibit dynamic scaling similar to scaling of growing surfaces. It is demonstrated by numerical simulations of two variants of the model in which nodes are added as well as removed [Phys.…

Statistical Mechanics · Physics 2009-11-07 Miroslav Kotrla , Frantisek Slanina , Jakub Steiner

We describe a numerical simulation of the evolution of an $S_3$ cosmic string network which takes fully into account the non-commutative nature of the cosmic string fluxes and the topological obstructions which hinder strings from moving…

Astrophysics · Physics 2009-10-30 Patrick N. McGraw