nucl-th digest · Dec 15, 2022

Bayesian Inference of the Dense Matter Equation of State built upon Covariant Density Functionals

A modified version of the density dependent covariant density functional model proposed in [T. Malik, M. Ferreira, B. K. Agrawal and C. Providência, ApJ 930, 17 (2022)] is employed in a Bayesian analysis to determine the equation of state (EOS) of dense matter with nucleonic degrees of freedom. Various constraints from nuclear physics and microscopic calculations of pure neutron matter (PNM) along with a lower bound on the maximum mass of neutron stars (NSs) are imposed on the EOS models to investigate the effectiveness of progressive incorporation of the constraints, their compatibility as well as correlations among parameters of nuclear matter and properties of NSs. Our results include the different roles played by pressure and energy per particle of PNM in constraining the isovector behavior of nuclear matter; tension with the values of Dirac effective mass extracted from spin-orbit splitting; correlations between the radius of the canonical mass NS and second and third order coefficients in the Taylor expansion of energy per particle as a function of density; correlation between the central pressure of the maximum mass configuration and Dirac effective mass of the nucleon at saturation. For some of our models the tail of the NS maximum mass reaches

2.7 M_{⊙}

, which means that the secondary object in GW190814 could have been a NS.

nucl-thastro-ph.HEPRC(2023)·38 citations

Temperature Dependence of Gluon and Ghost Propagators in a Dyson-Schwinger Equations context

L. P. Kaptari🇷🇺

We investigate the finite-temperature structure of ghost and gluon propagators within an approach based on the rainbow truncated Dyson-Schwinger equations in Landau gauge. The method, early used for modeling the quark, ghost and gluon propagators in vacuum, is extended to finite temperatures. In Euclidean space, within the Matsubara imaginary-time formalism it is necessary to distinguish between the transversal and longitudinal, with respect to the heat bath, gluon dressing functions, for which the Dyson-Schwinger equation splits into a corresponding system of coupled equations. This system is considered within the rainbow approximation generalized to finite temperatures and solved numerically. The solutions for the ghost and gluon propagators are obtained as functions of temperature $T$ , Matsubara frequency $Ω_{n}$ and three-momentum squared $k^{2}$ . It is found that, for zero Matsubara frequency, the dependence of the ghost and gluon dressing functions on $k^{2}$ are not sensitive to the temperature $T$ , while at $k^{2} = 0$ their dependence on $T$ is quite strong. Dependence on the Matsubara frequency $Ω_{n}$ is investigated as well.The performed numerical analysis of the solution of the Dyson-Schwinger equations shows that at certain value of the temperature $T_{0} \sim 150$ MeV the iteration procedure does not longer converge. In the vicinity of $T_{0}$ the longitudinal gluon propagator increases quite fastly, whereas the transversal propagator does not exhibit any irregularity. This in a qualitative agreement with results obtained within the QCD lattice calculations in this temperature interval.

↳ hep-phnucl-th0 citations

Thursday·December 15, 2022

Bayesian Inference of the Dense Matter Equation of State built upon Covariant Density Functionals

Temperature Dependence of Gluon and Ghost Propagators in a Dyson-Schwinger Equations context

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