Remya Nair

Post Doc at IUCAA

The idea of using Gravitational wave (GW) measurements to constrain cosmological parameters like the Hubble constant goes back to Schutz (1986) when he proposed that kilometer sized GW interferometers can be used to constrain the Hubble constant to an accuracy of 3 % using observations of coalescing double neutron star binaries. Distance estimates obtained from GW measurements are not biased by the distance ladder that plague the supernovae distances. But the major handicap in using GW measurements to constrain cosmology is the absence of redshift information. We are also looking at this problem and studying ho wone can estimate the source redshift in the absence of an electro-magnetic counterpart for a binary coalescence events. We are also looking at the idea of stacking up data for searching continuous GW sources. Here if one simply adds the data streams there is no guarantee that the signal would be added in phase, and one may actually end up losing valuable signal. We are studying ways for phase coherent additions.