Improved Upper Limits on the Stochastic Gravitational-Wave Background from 2009–2010 LIGO and Virgo Data

Authors

J. Aasi
B. P. Abbott
H. Daveloza
Mario C. Diaz, The University of Texas Rio Grande ValleyFollow
S. R. Morriss
Soma Mukherjee, The University of Texas Rio Grande ValleyFollow
M. E. Normandin
O. Puncken
Volker Quetschke, The University of Texas Rio Grande ValleyFollow
Malik Rakhmanov, The University of Texas Rio Grande ValleyFollow
Karla E. Ramirez, The University of Texas Rio Grande Valley
Joseph D. Romano, The University of Texas Rio Grande ValleyFollow
Robert Stone, The University of Texas Rio Grande Valley

Document Type

Article

Publication Date

12-2014

Abstract

Gravitational waves from a variety of sources are predicted to superpose to create a stochastic background. This background is expected to contain unique information from throughout the history of the Universe that is unavailable through standard electromagnetic observations, making its study of fundamental importance to understanding the evolution of the Universe. We carry out a search for the stochastic background with the latest data from the LIGO and Virgo detectors. Consistent with predictions from most stochastic gravitational-wave background models, the data display no evidence of a stochastic gravitational-wave signal. Assuming a gravitational-wave spectrum of ΩGWðfÞ ¼ Ωαðf=fref Þα, we place 95% confidence level upper limits on the energy density of the background in each of four frequency bands spanning 41.5–1726 Hz. In the frequency band of 41.5–169.25 Hz for a spectral index of α ¼ 0, we constrain the energy density of the stochastic background to be ΩGWðfÞ < 5.6 × 10−6. For the 600–1000 Hz band, ΩGWðfÞ < 0.14ðf=900 HzÞ3, a factor of 2.5 lower than the best previously reported upper limits. We find ΩGWðfÞ < 1.8 × 10−4 using a spectral index of zero for 170–600 Hz and ΩGWðfÞ < 1.0ðf=1300 HzÞ3 for 1000–1726 Hz, bands in which no previous direct limits have been placed. The limits in these four bands are the lowest direct measurements to date on the stochastic background. We discuss the implications of these results in light of the recent claim by the BICEP2 experiment of the possible evidence for inflationary gravitational waves.

Comments

© 2014 American Physical Society. Original published version available at https://doi.org/10.1103/PhysRevLett.113.231101

Recommended Citation

Aasi, J., et al. “Improved Upper Limits on the Stochastic Gravitational-Wave Background from 2009--2010 LIGO and Virgo Data.” Physical Review Letters, vol. 113, no. 23, American Physical Society, Dec. 2014, p. 231101, https://doi.org/10.1103/PhysRevLett.113.231101

Publication Title

Physical Review Letters

DOI

10.1103/PhysRevLett.113.231101