Quasar variability limits on cosmological density of cosmic strings

2010/01/31 by Artem V. Tuntsov, Artem Tuntsov, М. С. Пширков +1 · 15 citations
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Brightness #COSMIC cancer database #Cosmic string #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Galaxy #Omega #Physics #Quantum mechanics #Quasar #String (physics) #Theoretical physics #astro-ph.CO #gr-qc #hep-ph

paper · pdf · doi:10.1103/physrevd.81.063523

published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 81(6) (American Physical Society) · 7 pages, 2 figures, accepted to Phys.Rev.D, no essential changes from v1. Based on the referee's feedback, a paragraph is added that emphasizes the value of the obtained limits to constrain the abundance and reconnection probabilities of fundamental (rather than topological) strings

arxiv created 2010/02/24 · openalex publication_date 2010/03/16 · arxiv updated 2010/04/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We put robust upper limits on the average cosmological density \ensuremathΩ_s of cosmic strings based on the variability properties of a large homogeneous sample of Sloan Digital Sky Survey quasars. We search for an excess of characteristic variations of quasar brightness that are associated with string lensing and use the observed distribution of these variations to constrain the density of strings. The limits obtained do not invoke any clustering of strings. They apply to both open segments and closed loops of strings, usefully extend over a wide range of tensions 10^\ensuremath-13<G\ensuremathμ/c²<10^\ensuremath-9, and reach down to the level of \ensuremathΩ_s=0.01 and below. Further progress in this direction will depend on better understanding of quasar intrinsic variability rather than a mere increase in the volume of data.

Citations

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