Neutron star merger events are unique laboratories for exploring matter under extreme temperatures and densities. These conditions might harbor exotic particles like hyperons. In this talk I will discuss how the presence of hyperons influences the properties of matter (equation of state) and how this manifests in observable phenomena. The main focus will be on the distinct signatures arising...

The cores of neutron stars (NS) reach densities several times the nuclear saturation density and could contain strangeness containing exotic particles such as hyperons. During the binary inspiral, viscous processes inside the NS matter can damp out the tidal energy induced by the companion and convert this to thermal energy to heat up the star. We demonstrate that the bulk viscosity...

We show that results for the thermodynamics of strongly interacting matter obtained by state of the art Monte-Carlo simulations of lattice QCD can be adequately described within a generalized Beth-Uhlenbeck type approach, where the hadron resonance gas (HRG) phase appears as a statistical ensemble of multi-quark clusters. The underlying chiral quark dynamics is coupled to a background gluon...

We propose a scenario where the existence of a scalar, electrically neutral flavor-singlet three-diquark bound state, the light sexaquark S(uuddss), with a mass well below the double-Λ threshold M_{ΛΛ} = 2231.4 MeV entails the gravitational instability of low-mass neutron stars due to its Bose-Einstein condensation (BEC) [1]. Since in this state the neutron star core loses the pressure support...

We propose a modification to the relativistic mean-field $\sigma-\omega$ model by incorporating the Pauli-blocking effect arising from quark exchange interactions between baryons. In dense baryonic matter, where nucleon wave functions exhibit finite overlap, the quark exchange effects governed by the Pauli principle become significant at high densities. A quantitative estimate for this process...

We examine which first order phase transitions are consistent with today's astrophysical constraints. In particular, we explore how a well-constrained mass-radius data point would restrict the admissible parameter space and to this end, we employ the most likely candidates of the recent NICER limits of PSR J0030+0451. To systematically vary the stiffness of the equation of state, we employ a...

We study quasinormal $f-$mode oscillations in neutron star(NS) interiors within the linearized General Relativistic formalism. We utilize approximately 9000 nuclear Equations of State (EOS) using spectral representation techniques, incorporating constraints on nuclear saturation properties, chiral Effective Field Theory ($\chi$EFT) for pure neutron matter, and perturbative Quantum...

The massive stars end their lives by supernova explosions leaving central compact objects that may evolve into neutron stars. Initially, after birth, the star remains hot and gradually cools down. We explore the matter and star properties during this initial stage of the compact stars considering the possibility of the appearance of deconfined quark matter in the core of the star. Nonradial...

This study investigates the radial oscillations of hybrid neutron stars, characterized by a composition of hadronic external layers and a quark matter core. Utilizing a density-dependent relativistic mean-field model that incorporates hyperons and $\Delta$ baryons for describing hadronic matter, and a density-dependent quark model for quark matter, we analyze the ten lowest eigenfrequencies...

The saturation properties of symmetric and asymmetric nuclear matter have been computed using the finite range simple effective interaction (SEI) having Yukawa form factor. The results for higher order derivatives of the energy per particle and the symmetry energy computed at saturation, namely,$Q_0$, $K_{sym}$, $K_\tau$, $Q_{sym}$, are compared with the corresponding range of values...

The quest to constrain the equation of state (EoS) of ultra-dense matter and thereby probe the behaviour of matter inside neutron stars core is one of the main goals of modern astrophysics. A promising method involves investigating the long-term cooling of neutron stars, comparing theoretical predictions with various sources at different ages. However, limited observational data and...

In this talk I will present a method to compute the properties of dilute nuclear matter from quantum field theory at finite density. This approach provides a parameter-free calculation of the energy per particle of nuclear matter relying only on experimental nucleon-nucleon phase shifts. As a practical application we will show our predictions for the equation of state of dilute symmetric and...

We have recently provided the generic band of equations of state for matter at attainable densities in zero- and finite-temperature neutron stars restricted only by hadronic physics and fundamental principles, which are crucial for testing General Relativity and theories beyond it. We also characterise any first-order phase transitions therein by the specific latent heat, which we have...

Neutron stars unite several extremes of physics which cannot be recreated on Earth, making them excellent cosmic laboratories for studying the properties of ultra-dense matter. One exciting characteristic is the presence of superfluid and superconducting components in mature neutron stars. Albeit created under very different circumstances, such macroscopic quantum behaviour exhibits many...

In this work, we perform a Bayesian analysis putting together the available knowledge from the nuclear physics experiments and astrophysical observations to explore the equation of state of supranuclear matter. In particular, we employ a relativistic metamodeling technique to nuclear matter to cover the uncertainties in the parameter space of the saturation properties of nuclear matter, both...

Explaining gravitational-wave (GW) observations of binary neutron star (BNS) mergers requires an understanding of matter beyond nuclear saturation density. Our current knowledge of the properties of high-density matter relies on electromagnetic and GW observations, nuclear physics experiments, and general relativistic numerical simulations. We perform numerical-relativity simulations of BNS...

In our work we present general predictions for the static observables of neutron stars (NSs) under the hypothesis of a purely nucleonic composition of the ultra-dense baryonic matter, using Bayesian inference on a very large parameter space conditioned by both astrophysical and nuclear physics constraints.

The equation of states are obtained using a unified approach of the NS core and...

The long-sought equation of state of hadronic matter across a wide range of densities and temperatures, based on first principles with quarks and gluons i.e. quantum chromodynamics remains one of the key issues in physics. Over the past decade, a widely rich variety of data pouring in from laboratory experiments as well as astrophysical observations, including the detection of gravitational...