title: Upper limit on a stochastic background of gravitational waves from seismic measurements in the range 0.05-1 Hz.
abstract: In this Letter, we present an upper limit of ΩGW<1.2×108 on an isotropic stochastic gravitational-wave (GW) background integrated over a year in the frequency range 0.05-1 Hz, which improves current upper limits from high-precision laboratory experiments by about 9 orders of magnitude. The limit is obtained using the response of Earth itself to GWs via a free-surface effect described more than 40 years ago by Dyson. The response was measured by a global network of broadband seismometers selected to maximize the sensitivity.
authors.affiliation: Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Coughlin
authors.affiliation: INFN, Sezione di Firenze, Sesto Fiorentino 50019, Italy.
authors.forename: Jan
authors.initials: J
authors.lastname: Harms