skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The bispectrum of cosmic string temperature fluctuations including recombination effects

Abstract

We calculate the cosmic microwave background temperature bispectrum from cosmic strings, including the contributions from the last scattering surface, using a well-established Gaussian model for the string energy-momentum correlation functions, and a simplified model for the cosmic fluid. We check our approximation for the integrated Sachs-Wolfe (ISW) contribution against the bispectrum obtained from the full sky map of the cosmic string ISW signal used by the Planck team, obtaining good agreement. We validate our model for the last scattering surface contribution by comparing the predicted temperature power spectrum with that obtained from a full Boltzmann code treatment applied to the Unconnected Segment Model of a string network. We find that including the last scattering contribution has only a small impact on the upper limit on the string tension resulting from the bispectrum at Planck resolutions, and argue that the bispectrum is unlikely to be competitive with the power spectrum at any resolution.

Authors:
;  [1]
  1. Astronomy Centre, University of Sussex, Falmer, Brighton, BN1 9QH (United Kingdom)
Publication Date:
OSTI Identifier:
22525248
Resource Type:
Journal Article
Journal Name:
Journal of Cosmology and Astroparticle Physics
Additional Journal Information:
Journal Volume: 2015; Journal Issue: 10; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1475-7516
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; APPROXIMATIONS; COMPARATIVE EVALUATIONS; CORRELATION FUNCTIONS; COSMOLOGY; ENERGY SPECTRA; FLUCTUATIONS; FLUIDS; RECOMBINATION; RELICT RADIATION; RESOLUTION; SCATTERING; SKY; STRING THEORY; SURFACES

Citation Formats

Regan, Donough, and Hindmarsh, Mark, E-mail: d.regan@sussex.ac.uk, E-mail: m.b.hindmarsh@sussex.ac.uk. The bispectrum of cosmic string temperature fluctuations including recombination effects. United States: N. p., 2015. Web. doi:10.1088/1475-7516/2015/10/030.
Regan, Donough, & Hindmarsh, Mark, E-mail: d.regan@sussex.ac.uk, E-mail: m.b.hindmarsh@sussex.ac.uk. The bispectrum of cosmic string temperature fluctuations including recombination effects. United States. doi:10.1088/1475-7516/2015/10/030.
Regan, Donough, and Hindmarsh, Mark, E-mail: d.regan@sussex.ac.uk, E-mail: m.b.hindmarsh@sussex.ac.uk. Thu . "The bispectrum of cosmic string temperature fluctuations including recombination effects". United States. doi:10.1088/1475-7516/2015/10/030.
@article{osti_22525248,
title = {The bispectrum of cosmic string temperature fluctuations including recombination effects},
author = {Regan, Donough and Hindmarsh, Mark, E-mail: d.regan@sussex.ac.uk, E-mail: m.b.hindmarsh@sussex.ac.uk},
abstractNote = {We calculate the cosmic microwave background temperature bispectrum from cosmic strings, including the contributions from the last scattering surface, using a well-established Gaussian model for the string energy-momentum correlation functions, and a simplified model for the cosmic fluid. We check our approximation for the integrated Sachs-Wolfe (ISW) contribution against the bispectrum obtained from the full sky map of the cosmic string ISW signal used by the Planck team, obtaining good agreement. We validate our model for the last scattering surface contribution by comparing the predicted temperature power spectrum with that obtained from a full Boltzmann code treatment applied to the Unconnected Segment Model of a string network. We find that including the last scattering contribution has only a small impact on the upper limit on the string tension resulting from the bispectrum at Planck resolutions, and argue that the bispectrum is unlikely to be competitive with the power spectrum at any resolution.},
doi = {10.1088/1475-7516/2015/10/030},
journal = {Journal of Cosmology and Astroparticle Physics},
issn = {1475-7516},
number = 10,
volume = 2015,
place = {United States},
year = {2015},
month = {10}
}