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Related papers: CMB constraints on cosmic strings and superstrings

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We simulate the anisotropy in the cosmic microwave background (CMB) induced by cosmic strings. By numerically evolving a network of cosmic strings we generate full-sky CMB temperature anisotropy maps. Based on $192$ maps, we compute the…

Astrophysics · Physics 2008-11-26 B. Allen , R. R. Caldwell , E. P. S. Shellard , A. Stebbins , S. Veeraraghavan

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 present the first CMB power spectra from numerical simulations of the global O(N) linear $\sigma$-model with N = 2,3, which have global strings and monopoles as topological defects. In order to compute the CMB power spectra we compute…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-28 Asier Lopez-Eiguren , Joanes Lizarraga , Mark Hindmarsh , Jon Urrestilla

The recent observation that the Cosmic Microwave Background (CMB) may prefer a neutrino excess has triggered a number of works studying this possibility. The effect obtained by the non-interacting massless neutrino excess could be mimicked…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Joanes Lizarraga , Irene Sendra , Jon Urrestilla

Standard D-term inflation is studied in the framework of supergravity. D-term inflation produces cosmic strings, however it can still be compatible with CMB measurements without invoking any new physics. The cosmic strings contribution to…

High Energy Physics - Phenomenology · Physics 2009-11-10 Jonathan Rocher , Mairi Sakellariadou

We present a cosmic string on a warped five dimensional space time in Einstein-Yang-Mills theory. Four-dimensional cosmic strings show some serious problems concerning the mechanism of string smoothing related to the string mass per unit…

General Relativity and Quantum Cosmology · Physics 2011-11-14 Reinoud Jan Slagter , Derk Masselink

Cosmic strings generate vector and tensor modes in the B-channel of polarization, as well as the usual temperature power spectrum and E-mode polarization spectrum. We use the power spectrum obtained from high-resolution Nambu-Goto cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2015-02-25 Andrei Lazanu , E. P. S. Shellard

Cosmic strings can arise in hidden sector models with a spontaneously broken Abelian symmetry group. We have studied the couplings of the Standard Model fields to these so-called dark strings in the companion paper. Here we survey the…

High Energy Physics - Phenomenology · Physics 2015-06-23 Andrew J. Long , Tanmay Vachaspati

In this work, we consider a network of cosmic strings to explain possible deviation from \Lambda CDM behaviour. We use different observational data to constrain the model and show that a small but non zero contribution from the string…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Sumit Kumar , Akhilesh Nautiyal , Anjan A. Sen

Cosmic strings are expected to form loops. These can act as seeds for accretion of dark matter, leading to the formation of ultracompact minihalos (UCMHs). We perform a detailed study of the accretion of dark matter onto cosmic string loops…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-22 Madeleine Anthonisen , Robert Brandenberger , Pat Scott

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

This paper deals with the geometry of supermassive cosmic strings. We have used an approach that enforces the spacetime of cosmic strings to also satisfy the conservation laws of a cylindric gravitational topological defect, that is a…

General Relativity and Quantum Cosmology · Physics 2009-10-28 P. F. Gonzalez-Diaz

We review the properties and evolution of strings networks containing both a spectrum of string tensions as well as Y-junctions, namely a point at which three different strings meet. Such a situation is expected in cosmic superstring…

High Energy Physics - Theory · Physics 2015-06-17 D. A. Steer

We point out that the inclusion of a string component contributing around 5% to the CMB power spectrum amplitude on large scales can increase the preferred value of the spectral index n_s of density fluctuations measured by CMB experiments.…

Astrophysics · Physics 2009-11-11 Richard A. Battye , Bjorn Garbrecht , Adam Moss

In a recent publication, we used the data from WMAP and SDSS to constrain the primordial perturbations and to predict the B-mode polarization sourced by cosmic string networks. We have been alerted by A. Slosar to the existence of errors in…

Astrophysics · Physics 2007-05-23 Levon Pogosian , Ira Wasserman , Mark Wyman

We show that the existence of cosmic strings can be strongly constrained by the next generation of gravitational lensing surveys at radio frequencies. We focus on cosmic string loops, which simulations suggest would be far more numerous…

Astrophysics · Physics 2008-11-26 Katherine J. Mack , Daniel H. Wesley , Lindsay J. King

We investigate a static, cylindrically symmetric cosmic string on the brane without a perturbative approximation. We find there could be a (large) enhancement of the (effective) string tension when the energy density at the center of the…

High Energy Physics - Theory · Physics 2023-04-12 Chia-Min Lin

Promptly after high-resolution experiments harbinger the field of precision cosmology low- and high-redshift observations abruptly gave rise to a tension in the measurement of the present-day expansion rate of the Universe ($H_0$) and the…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-08 Luis A. Anchordoqui , Ignatios Antoniadis , Dieter Lust , Neena T. Noble , Jorge F. Soriano

We compute the constraints on a ``standard'' 10 parameter cold dark matter (CDM) model from the most recent CMB and data and other observations, exploring 30 million discrete models and two continuous parameters. Our parameters are the…

Astrophysics · Physics 2009-09-25 Max Tegmark , Matias Zaldarriaga

Observations of the cosmic microwave background (CMB) together with weak lensing measurements of the clustering of large scale cosmological structures and local measurements of the Hubble constant pose a challenge to the standard…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-08 Marco Raveri , Wayne Hu , Timothy Hoffman , Lian-Tao Wang