Multimessenger constraints on the neutron-star equation of state and the Hubble constant

Observations of neutron-star mergers with distinct messengers, including gravitational waves and electromagnetic signals, can be used to study the behavior of matter denser than an atomic nucleus and to measure the expansion rate of the Universe as quantified by the Hubble constant. We performed a joint analysis of the gravitational-wave event GW170817 with its electromagnetic counterparts AT2017gfo and GRB170817A, and the gravitational-wave event GW190425, both originating from neutron-star mergers. We combined these with previous measurements of pulsars using x-ray and radio observations, and nuclear-theory computations using chiral effective field theory, to constrain the neutron-star equation of state. We found that the radius of a 1.4–solar mass neutron star is$11.75−0.81+0.86$km at 90% confidence and the Hubble constant is$66.2−4.2+4.4$at 1σ uncertainty.

Authors:
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Award ID(s):
Publication Date:
NSF-PAR ID:
10212685
Journal Name:
Science
Volume:
370
Issue:
6523
Page Range or eLocation-ID:
p. 1450-1453
ISSN:
0036-8075
Publisher:
American Association for the Advancement of Science (AAAS)
National Science Foundation
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