June 19, 2026: Andreas Konstantinou
Affiliation: Department of Physics, University of Cyprus, Nicosia, Cyprus
Title: Universal Relations for Rotating Neutron Stars
Abstract: Rapid rotation changes the structure of neutron stars, increasing both their equatorial radius and gravitational mass relative to corresponding non-rotating configurations. Because the dense-matter equation of state remains uncertain, especially at supranuclear densities, it is useful to identify relations that depend only weakly on the underlying microphysics. This presentation examines universal relations that map rotating neutron-star models to non-rotating ones using the fractional changes in mass and radius. The analysis focuses on equation-of-state-insensitive descriptions of rotating neutron stars and their usefulness for connecting observed rapidly rotating configurations to their non-rotating counterparts. Extensions of this work show that similar universal behavior persists in more exotic settings, including neutron stars with dark-matter cores, proto-neutron-star equations of state, and self-bound equations of state relevant to quark stars.
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