NEUMATT NEUtron star MATter Theory
The Equation of State of Nuclear Matter and Neutron Star Structure


The project aims at studying various aspects of neutron stars (NSs), fostering the investigation of the relevant microphysics and its interplay with the structure and composition of compact stars. This research is particularly timely, due to the abundance of experimental data expected in the near future from a variety of detectors: X-ray detectors (NICER, AthenaPlus), radiotelescopes (SKA) and upgraded gravitational wave (GW) detectors (LIGO, VIRGO). Moreover, the analysis of explosive phenomena such as Supernovae (SN) and Gamma Ray Bursts can provide fundamental clues to the still elusive nature of compact stars. The composition of a compact star will reflect onto its mass-radius relation, its moment of inertia, its rotational properties and it will leave an imprint on the GW emission during the merger of two compact stars. Therefore, future more refined observational data can be used to scrutinize many properties of neutron star matter in greater detail. In the last years a problem has emerged with increasing evidence: the difficulty to reconcile the existence of very massive compact stars with the theoretical indications of the softening of the Equation of State (EoS) due to the possible appearance of hyperons (and of other resonances) at densities reachable inside compact stars. The solution of this puzzle could be the stiffening of the EoS due to repulsive many-body interactions and/or the appearance of deconfined quark matter. Regarding the long-standing puzzle of the presence of deconfined quark matter, its formation should lead to a huge release of energy which can be associated to specific observed emissions during explosive phenomena. In SNs most of the released energy is carried out by neutrinos, detectable in underground experiments, if the source is not too far away. Finally, the structure of the crust influences the thermal evolution of the compact star and it is likely connected with transients as the stellar glitches, which can provide valuable information on superfluid nuclear matter. In conclusion, the aim of our research is to provide crucial links between the microphysics of compact stars and the huge variety of forthcoming observational data.