http://arxiv.org/abs/1710.06370
The recent observations of gravitational-wave and electromagnetic emission produced by the merger of the binary neutron-star system GW170817 have opened the possibility of using standard siren to constrain the value of the Hubble constant. While the reported bound is significantly weaker than those recently derived by usual luminosity distances methods, they do not require any form of cosmic distance ladder and can be considered as complementary and, in principle, more conservative. Here we combine the new measurement with the Planck Cosmic Microwave Background observations in a 12 parameters extended LambdaCDM scenario, where the Hubble constant is weakly constrained by CMB data and bound to a low value $H_0=55^{+7}_{-20}$ km/s/Mpc at 68 % C.L. The non-Gaussian shape of the GW170817 bound makes lower values of the Hubble constant in worst agreement with observations. The inclusion of the new GW170817 Hubble constant measurement significantly reduces the allowed parameter space, improving the cosmological bounds on several parameters as the neutrino mass, curvature and the dark energy equation of state.
E. Valentino and A. Melchiorri
Wed, 18 Oct 2017
7/62
Comments: 5 pages, 4 Figures