Thesis

Thermal evolution of hybrid stars

• Call:

  PT-CERN Call 2021/1

• Academic Year:

  2021

• Domain:

  Astroparticle Physics

• Supervisor:

  Constança Providência

• Co-Supervisor:

  Violetta Sagun

• Institution:

  Universidade de Coimbra

• Host Institution:

  CFISUC - Centro de Fisica da Universidade de Coimbra

• Abstract:

  The compact astrophysical objects, i.e. neutron stars (NSs), hypothetical hybrid (HSs) and quark stars (QSs), are the most dense physical objects accessible by direct observations. Despite the flourishing of astrophysical observations, the internal particle composition of compact stars remains very poorly known. Moreover, the physical processes inside hypothetical objects like HSs and QSs, for which is expected that matter undergoes a phase transition from nuclear matter to a plasma of strongly interacting quarks, are equally poorly understood. This limitation stems from the fact that QCD and its lattice formulation have very limited applicability at large baryonic densities thus not allowing for obtaining a reliable equation of state (EoS). Detection of a QS/HS can become another scientific breakthrough and prove the existence of quark matter, which is the main quest of large research collaborations, such as ALICE at the Large Hadron Collider (LHC) in CERN. Compact stars cool down through a combination of thermal radiation from their surface and neutrino emission from their interior. Observational data of the surface temperature and luminosity of stars provide valuable information about their internal composition, the EoS, the chemical abundances of the envelope and the degree, type and model of pairing of their constituent particles. Studying the thermal evolution of compact objects with a quark core is the primary goal of this research project. Existence of the quark-hadron phase transition, as well as other phase transitions to a denser phase of quark matter, will affect the dynamics of the HS cooling. Their modeling can provide the community with a valuable opportunity to investigate the properties of phase transitions, as well as the EoS of strongly interacting matter at high densities. Finally, this PhD project will also examine the impact of pairing between quarks on the thermal evolution of HS, probing the densest predicted region of the QCD phase diagram.