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SUMMARY:A gravitational-wave standard siren measurement of the Hubble cons
 tant - Dr Jonathan Gair (University of Edinburgh)
DTSTART:20180518T120000Z
DTEND:20180518T130000Z
UID:TALK106246@talks.cam.ac.uk
CONTACT:Michalis Agathos
DESCRIPTION:On 17th August 2017\, the Advanced LIGO and Virgo interferomet
 ers observed gravitational waves from the inspiral and merger of a binary 
 neutron star system for the first time. An optical counterpart to the even
 t was observed the following night\, which allowed the unique identificati
 on of the host galaxy of the event and hence a determination of its redshi
 ft. The combination of a measurement of luminosity distance from the gravi
 tational wave signal with the electromagnetic redshift measurement allowed
  the local expansion rate of the Universe\, the Hubble constant\, to be es
 timated. The final result\, H0 = 70 +12/-8 km/s/Mpc\, is consistent with c
 urrent electromagnetic measurements\, albeit not competitive with their pr
 ecision. However\, such standard siren measurements of cosmological parame
 ters are largely independent of existing techniques and hence will provide
  a powerful verification of these other results. In this talk I will provi
 de details of the first gravitational wave Hubble constant measurement and
  then discuss prospects for improving this result over the next two decade
 s\, using further binary neutron star mergers with counterparts\, using st
 atistical cross-correlation of gravitational wave events with galaxy catal
 ogues in the absence of counterparts and using sources observed with other
  planned gravitational wave detectors.
LOCATION:Pavilion B Potter Room (B1.19)
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