Light (e.g. deuterons, tritons, helions, α−particles), and heavy (pasta phases) nuclei exist in nature in core-collapse supernova matter and neutron star (NS) mergers, where temperatures of the order of 50 to 100 MeV may be attained. In the NS inner crust, that is under different conditions of temperature, density and asymmetry, these heavy clusters should also be present. The appearance of these clusters can modify the neutrino transport, and, therefore, consequences on the dynamical evolution of supernovae and on the cooling of proto-neutron stars are expected. However, a correct estimation of their abundance implies that an in-medium
modification of their binding energies is precisely derived. At such high temperatures, other exotic degrees of freedom, such as hyperons and ∆−isobars, may appear.
In this talk, we will start with a short introduction on compact objects, the equation of state and its constraints. Then we will address the low-density equation of state where we consider light clusters. We will consider not only from the theoretical point of view how these light clusters are calculated for warm stellar matter in the framework of relativistic mean-field (RMF) models with in-medium effects, but also how these models are calibrated to experimental data from heavy-ion collisions, measured by the INDRA Collaboration. We show that this in-medium correction, which was not considered in previous analyses from heavy-ion collisions, is
necessary, since the observables of the analyzed systems show strong deviations from the expected results for an ideal gas of free clusters. It turns out that the resulting light cluster abundances come out to be in reasonable agreement with constraints at higher density coming from heavy ion collision data.
Organized by: Catarina Cosme