Upper limits on a stochastic gravitational-wave background using LIGO and Virgo interferometers at 600-1000 Hz

Abstract

Astochasticbackgroundofgravitationalwavesisexpectedtoarisefromasuperpositionofmanyincoherentsourcesofgravitationalwaves,ofeithercosmologicalorastrophysicalorigin.Thisbackgroundisatargetforthecurrentgenerationofground-baseddetectors.InthisarticlewepresentthefirstjointsearchforastochasticbackgroundusingdatafromtheLIGOandVirgointerferometers.Inafrequencybandof600-1000Hz,weobtaineda95%upperlimitontheamplitudeofΩgw(f)=Ω3(f/900Hz)(3),ofΩ3lessthan0.33,assumingavalueoftheHubbleparameterofh100=0.72.Thesenewlimitsareafactorofsevenbetterthanthepreviousbestinthisfrequencyband.