Sengupta, Anand et al.Anand et al.Sengupta2025-08-302025-08-302017-03-2410.1103/PhysRevLett.118.1211012-s2.0-85016165596https://repository.iitgn.ac.in/handle/IITG2025/2251528388180A wide variety of astrophysical and cosmological sources are expected to contribute to a stochastic gravitational-wave background. Following the observations of GW150914 and GW151226, the rate and mass of coalescing binary black holes appear to be greater than many previous expectations. As a result, the stochastic background from unresolved compact binary coalescences is expected to be particularly loud. We perform a search for the isotropic stochastic gravitational-wave background using data from Advanced Laser Interferometer Gravitational Wave Observatory's (aLIGO) first observing run. The data display no evidence of a stochastic gravitational-wave signal. We constrain the dimensionless energy density of gravitational waves to be Ω0<1.7×10-7 with 95% confidence, assuming a flat energy density spectrum in the most sensitive part of the LIGO band (20-86 Hz). This is a factor of ∼33 times more sensitive than previous measurements. We also constrain arbitrary power-law spectra. Finally, we investigate the implications of this search for the background of binary black holes using an astrophysical model for the background.falseArticlehttp://link.aps.org/pdf/10.1103/PhysRevLett.118.1211011079711424 March 2017247121101224WOS:000397805800003