Speaker
Description
This work presents the rotational properties of self-bound quark stars within general relativity using two representative quark matter equations of state: the vector MIT bag model and the density-dependent quark mass model. Uniformly rotating equilibrium sequences are constructed to explore their mass--radius relations, moments of inertia, quadrupole moments, surface redshifts, Keplerian frequencies, and rotational energy components. A key outcome of this work is a detailed decomposition of the stellar energy budget, explicitly separating gravitational, internal, rotational, and binding energy contributions in rotating quark stars. We find that rotation accentuates intrinsic differences between the equations of state: the MIT model supports more massive configurations ($M_{\max}\gtrsim 3.3\,M_\odot$) with larger moments of inertia and reduced deformability, whereas the DDQM model yields stars with larger radii that reach the mass-shedding limit at lower spin frequencies. We show that combined measurements of mass, radius, and spin frequency can break degeneracies between quark matter models, with massive, rapidly rotating pulsars favoring MIT-like equations of state, while larger radii in canonical-mass stars point to DDQM-like behavior. These rotational observables, increasingly accessible through \textit{NICER} observations and next-generation gravitational-wave detectors, provide a promising avenue to test the existence and properties of self-bound quark matter in compact stars.
