2 research outputs found

    A search for tensor, vector, and scalar polarizations in the stochastic gravitational-wave background

    Get PDF
    The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually-unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically-polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy-densities of tensor, vector, and scalar modes at 95% credibility to ΩT0<5.6×10−8, ΩV0<6.4×10−8, and ΩS0<1.1×10−7 at a reference frequency f0=25 Hz.by Anand Sengupta et al

    All-sky search for continuous gravitational waves from isolated neutron stars using Advanced LIGO O2 data

    Get PDF
    We present results of an all-sky search for continuous gravitational waves (CWs), which can be produced by fast spinning neutron stars with an asymmetry around their rotation axis, using data from the second observing run of the Advanced LIGO detectors. Three different semicoherent methods are used to search in a gravitational-wave frequency band from 20 to 1922 Hz and a first frequency derivative from -1 x 10(-8) to 2 x 10(-9) Hz/s. None of these searches has found clear evidence for a CW signal, so upper limits on the gravitational-wave strain amplitude are calculated, which for this broad range in parameter space are the most sensitive ever achieved
    corecore