Non-local quark models for description of dense matter in the cores of neutron stars

Abstract

This thesis work focuses on studying the possible existence of phase transitions in the immediate compact remnants of core collapse supernova, neutron stars, and the theoretical models that describe the interior of dense matter. Specifically, we are interested in analyzing the feasibility of a transition from hadronic matter to quark matter in the cores of these objects. For the phase transition we will use two different formalisms: the Maxwell formalism or abrupt phase transition and the Gibbs formalisms or mixed phase transition. For the description of hadronic matter, we will use different parametrizations of the relativistic mean field model with density-dependent coupling constants. For the description of quark matter we will use an effective nonlocal Nambu Jona-Lasinio model of three flavors with vector interactions, in which we will include the possibility of formation of diquarks to model a superconducting phase of color in $SU(3)$. Phase diagrams and equations of state of quark matter at finite temperature are presented, and the influence of that type of matter on observables associated with neutron stars is investigated. The simplified thermal evolution of compact stars during their formation is studied, from their state of proto-neutron stars to that of cold neutron stars, and the results obtained are compared with recent astrophysical observations. The results obtained indicate that the occurrence of quark matter in the nuclei of these stars remains a promising possibility. The fact that the use of more realistic models for the description of the dense matter in these objects indicates the presence of quark matter inside neutron stars, could be an answer to the question of the behavior of that kind of matter and the determination of its corresponding equation of state.

140 pages, 29 figures, PhD Thesis

References in corpus (11)

• A Massive Pulsar in a Compact Relativistic Binary
• The QCD transition temperature: results with physical masses in the continuum limit II.
• Relativistic model for nuclear matter and atomic nuclei with momentum-dependent self-energies
• Pulsars as Astrophysical Laboratories for Nuclear and Particle Physics
• The chiral and deconfinement crossover transitions: PNJL model beyond mean field
• Phase transition dynamics for baryon-dense matter
• Model study of the sign problem in the mean-field approximation
• Nonlocal SU(3) chiral quark models at finite temperature: the role of the Polyakov loop
• Hybrid stars within a covariant, nonlocal chiral quark model
• Enforced neutrality and color-flavor unlocking in the three-flavor Polyakov-loop NJL model
• Color neutrality effects in the phase diagram of the PNJL model