Microlensing by cosmic strings

Konrad Kuijken, Xavier Siemens, Tanmay Vachaspati

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

We consider the signature and detectability of gravitational microlensing of distant quasars by cosmic strings. Because of the simple image configuration such events will have a characteristic lightcurve, in which a source would appear to brighten by exactly a factor of 2, before reverting to its original apparent brightness. We calculate the optical depth and event rate, and conclude that current predictions and limits on the total length of strings on the sky imply optical depths of ≲ 10-8 and event rates of fewer than one event per 109 sources per year. Disregarding those predictions but replacing them with limits on the density of cosmic strings from the cosmic microwave background fluctuation spectrum, leaves only a small region of parameter space (in which the sky contains about 3 × 105 strings with deficit angle of the order of 0.3 milli-seconds) for which a microlensing survey of exposure 107 source years, spanning a 20-40-year period, might reveal the presence of cosmic strings.

Original languageEnglish (US)
Pages (from-to)161-164
Number of pages4
JournalMonthly Notices of the Royal Astronomical Society
Volume384
Issue number1
DOIs
StatePublished - Feb 2008
Externally publishedYes

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optical depth
strings
prediction
optical thickness
sky
predictions
leaves
quasars
brightness
signatures
rate
microwaves
configurations
exposure
microwave
parameter

Keywords

  • Cosmology: miscellaneous
  • Gravitational lensing

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Microlensing by cosmic strings. / Kuijken, Konrad; Siemens, Xavier; Vachaspati, Tanmay.

In: Monthly Notices of the Royal Astronomical Society, Vol. 384, No. 1, 02.2008, p. 161-164.

Research output: Contribution to journalArticle

Kuijken, Konrad ; Siemens, Xavier ; Vachaspati, Tanmay. / Microlensing by cosmic strings. In: Monthly Notices of the Royal Astronomical Society. 2008 ; Vol. 384, No. 1. pp. 161-164.
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