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Related papers: Cosmic string loops in the expanding universe

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The Pulsar timing data from NANOGrav Collaboration has regenerated interest in the possibility of observing stochastic gravitational wave background arising from cosmic strings. In the standard theory, the cosmic string network forms during…

General Relativity and Quantum Cosmology · Physics 2024-05-08 Ajit M. Srivastava

Generic cosmological models in non-critical string theory have a time-dependent dilaton background at a late epoch. The cosmological deceleration parameter Q_0 is given by the square of the string coupling, g_s^2, up to a negative sign.…

General Relativity and Quantum Cosmology · Physics 2014-11-17 John Ellis , N. E. Mavromatos , D. V. Nanopoulos

We investigate the non-gaussian properties of cosmic-string-seeded linear density perturbations with cold and hot dark matter backgrounds, using high-resolution numerical simulations. We compute the one-point probability density function of…

Astrophysics · Physics 2009-10-30 P. P. Avelino , E. P. S. Shellard , J. H. P. Wu , B. Allen

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 collapse of a circular loop of cosmic string. The gravitational field of the string is treated using the weak field approximation. The gravitational radiation from the loop is evaluated numerically. The memtric of the loop near…

General Relativity and Quantum Cosmology · Physics 2009-10-22 David Garfinkle , G. Comer Duncan

The existence of a scaling network of current-carrying cosmic strings in our Universe is expected to continuously create loops endowed with a conserved current during the cosmological expansion. These loops radiate gravitational waves and…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-30 Pierre Auclair , Patrick Peter , Christophe Ringeval , Daniele Steer

We account for particle emission and gravitational radiation from cosmic string loops to determine their effect on the loop distribution and observational signatures of strings. The effect of particle emission is that the number density of…

High Energy Physics - Phenomenology · Physics 2020-04-15 P. Auclair , D. A. Steer , T. Vachaspati

The topic of cosmic strings provides a bridge between the physics of the very small and the very large. They are predicted by some unified theories of particle interactions. If they exist, they may help to explain some of the largest-scale…

High Energy Physics - Phenomenology · Physics 2010-11-01 M. B. Hindmarsh , T. W. B. Kibble

Spectra of the stochastic gravitational wave backgrounds from cosmic strings are calculated and compared with present and future experimental limits. Background spectra are calculated numerically for dimensionless string tensions G mu/c^2…

Astrophysics · Physics 2008-11-26 Matthew R. DePies , Craig J. Hogan

We calculate the gravitational radiation emitted by an infinite cosmic string with two oppositely moving wave-trains, in the small amplitude approximation. After comparing our result to the previously studied cases we extend the results to…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Xavier Siemens , Ken D. Olum

We develop a model of string dynamics with back-reaction from both scaling and non-scaling loops taken into account. The evolution of a string network is described by the distribution functions of coherence segments and kinks. We derive two…

High Energy Physics - Theory · Physics 2010-11-19 Vitaly Vanchurin

Spin networks, the quantum states of discrete geometry in loop quantum gravity, are directed graphs whose links are labeled by irreducible representations of SU(2), or spins. Cosmic strings are 1-dimensional topological defects carrying…

General Relativity and Quantum Cosmology · Physics 2020-04-03 Barak Shoshany

Models of symmetry breaking in the early universe can produce networks of cosmic strings threading 't Hooft-Polyakov monopoles. In certain cases there is a larger global symmetry group and the monopoles split into so-called semipoles. These…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-13 Mark Hindmarsh , Anna Kormu , Asier Lopez-Eiguren , David J. Weir

We have studied the cosmological evolution of domain wall networks in two, three and four spatial dimensions using high-resolution field theory simulations. The dynamical range and number of our simulations is larger than in previous works,…

High Energy Physics - Phenomenology · Physics 2009-11-10 J. C. R. E. Oliveira , C. J. A. P. Martins , P. P. Avelino

In this paper the collision of two cosmic string loops is studied. After collision junctions are formed and the loops are entangled. We show that after their formation the junctions start to unzip and the loops disentangle. This analysis…

High Energy Physics - Theory · Physics 2009-11-06 Hassan Firouzjahi , Johanna Karouby , Shahram Khosravi , Robert Brandenberger

The formation of cusps on long cosmic strings is discussed and the probability of cusp formation is estimated. The energy distribution of the gamma-ray background due to cusp annihilation on long strings is calculated and compared to…

High Energy Physics - Phenomenology · Physics 2009-10-22 M. Mohazzab , R. H. Brandenberger

In a recent paper, the NANOGrav collaboration studied new physics explanations of the observed pulsar timing residuals consistent with a stochastic gravitational wave background (SGWB), including cosmic strings in the Nambu-Goto (NG)…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-31 Jun'ya Kume , Mark Hindmarsh

The idea of GUT implies that the universe went through a series of phase transitions during which topological defects are expected to form. We investigate here the genericity of cosmic strings formation in realistic SUSY GUTs models. We…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. Rocher , R. Jeannerot , M. Sakellariadou

The properties of cosmic strings have been investigated in detail for their implications in early-universe cosmology. Although many variations of the basic structure have been discovered, with implications for both the microscopic and…

High Energy Physics - Theory · Physics 2009-10-28 Ryan Rohm , Indranil Dasgupta

We search for stochastic gravitational wave background emitted from cosmic strings using the Parkes Pulsar Timing Array data over 15 years. While we find that the common power-law excess revealed by several pulsar timing array experiments…

High Energy Physics - Phenomenology · Physics 2022-11-23 Ligong Bian , Jing Shu , Bo Wang , Qiang Yuan , Junchao Zong