Following the idea that a light, compact sexaquark state with quark content (uuddss) might
might be a candidate for baryonic dark matter that has gone unnoticed by experiments so far
because its decay channels are practically closed [1], we investigate its possible role in the
physics of compact stars. We find that the stringent constraints on the equation of state
from mass and radius...
In my talk, I will present the results of a systematic investigation of the possible locations of the special point (SP), a unique feature of hybrid neutron stars manifesting in their mass-radius relation. The study demonstrates that the SP is invariant both to the choice of the low density hadronic equation of state (EoS) as well as to the two phase transition construction. This is shown in...
The interest in the equation of state (EoS) of nuclear matter has been renewed with the observation of gravitational waves from neutron star mergers. Since nuclear matter under similar conditions as in neutron star mergers can be studied in heavy ion collisions at low collision energies, additional information about the EoS can be extracted from the precise measurements performed at GSI or in...
The color superconducting phase with single flavor pairing can be relevant at environments inside the core of neutron stars. In this case, the ground state is described by the BCS pairing between quarks with opposite chirality. Very recently, Li and Haldane argue that the Cooper pair inherits a non-trivial topological structure from the underlying single-particle Berry monopole for...
We investigate the dynamical stability of neutron stars by performing radial perturbations on their stellar structure obtained after solving the hydrostatic-equilibrium equations which uses as input a collection of equations of state obtained from successive matchings between perturbative QCD at high densities and chiral effective theory at low densities and constrained by observational data...
The nature of the equation of state (EOS) of neutron stars is an open research problem. The high baryonic density and isospin asymmetry that characterize this system hinder first principle calculations of the EOS, its particle composition and in-medium particle interactions. Therefore, at the moment there is no consensus on the presence of quark matter in neutron star cores, or on the nuclear...
Interpreting high-energy, astrophysical phenomena, such as supernova explosions or neutron-star collisions, requires a robust understanding of matter at supranuclear densities. However, our knowledge about dense matter explored in the cores of neutron stars remains limited. Fortunately, dense matter is not only probed in astrophysical observations, but also in terrestrial heavy-ion collision...
In the core of neutron stars, extreme gravitational fields probe the stiffness of matter at very large densities. Recent neutron-star observations indicate that ultradense matter must be stiffer than previously thought, with the speed of sound potentially rising well above its asymptotic conformal limit of $1/\sqrt{3}$ [1]. Nonetheless, the implications of this large speed-of-sound peak for...
The question of whether quark matter exists in neutron stars is a long standing one. Generally one finds that a first order phase transition from baryons to quarks softens the equation of state so much that the star would collapse into a black hole. We consider a crossover equation of state, similar to the crossover that is found in lattice QCD studies at finite temperature and zero or small...
The existence of quark matter inside the cores of massive neutron stars can be probed by modern astrophysical observations. We model these hybrid stars using an (axial)vector meson extended quark-meson model to describe their quark cores, together with various hadronic models. We show that crossover phase transitions between the hadronic and quark phases can naturally create equations of state...
We study the possible existence of deconfine quark matter in the core of neutron stars. A relativistic mean field model is used to describe the nuclear matter at low densities while Nambu--Jona-Lasinio model is used to describe the quark matter at high densities. A Gibbs construct is used to describe the quark-hadron phase transition at large densities and at zero temperature. Within the...
Skyrme model is among the simplest extensions of chiral effective theory including anomaly. Within such framework we investigate how an external magnetic field deforms a Skyrmion while preserving its topological winding. A crystal constituted by multiple magnetically deformed Skyrmions provides us insights of the ground state of nuclear matter in strong magnetic field. We manifest such Skyrme...
The observation of gravitational waves from neutron stars opens up the possibility to learn about Quantum Chromodynamics at baryon densities above nuclear saturation and at very low temperatures. Interestingly, introducing non-trivial structure in the speed of sound sourced by changes in the degrees of freedom (possibly quarks) of ultra-dense matter can lead to extremely heavy neutron stars...
