Hybrid and quark star matter based on a nonperturbative equation of state

Otto, Konstantin; Oertel, Micaela; Schaefer, Bernd-Jochen

doi:10.1103/physrevd.101.103021

Cited by 66 publications

(61 citation statements)

References 119 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This rather soft EoS does not allow for the construction of hybrid stars with a three-flavor quark core in agreement with present neutron star mass measurements [2][3][4]. Therefore, here we will extent the work of [56] and investigate the impact of additional vector meson interactions. While the (pseudo)scalars fields are integrated out within the functional renormalization group framework, the vector mesons are treated on a constant background level.…”

Section: Introductionmentioning

confidence: 74%

“…equation (19), which in turn decreases the number density from its initial value, there is always a unique solution to the vector meson gap equation (23). Note that the assumption of one light chiral condensate for both the up and down flavors breaks down close to the chiral phase transition under the assumptions of β-equilibrium and charge neutrality [56]. Hence, only data points above the chiral phase transition in the light scalar sector with µ > 310 MeV are considered.…”

Section: Numerical Resultsmentioning

confidence: 99%

“…Nevertheless, within this framework, the impact of fluctuations in the (pseudo)scalar interaction channel on the compact star EoS has recently been studied [56]. It was found that the fluctuations decrease the sound speed of the quark matter even below the mean-field value of c 2 s = 1/3, leading to a rather soft EoS at high densities.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Nonperturbative quark matter equations of state with vector interactions

Otto

Oertel

Schaefer

2020

Eur. Phys. J. Spec. Top.

Self Cite

View full text Add to dashboard Cite

Nonperturbative equations of state (EoSs) for two and three quark flavors are constructed with the functional renormalization group (FRG) within a quark-meson model truncation augmented by vector mesons for low temperature and high density. Based on previous FRG studies without repulsive vector meson interactions the influence of isoscalar vector ω- and ϕ-mesons on the dynamical fluctuations of quarks and (pseudo)scalar mesons is investigated. The grand potential as well as vector meson condensates are evaluated as a function of quark chemical potential and the quark matter EoS in β-equilibrium is applied to neutron star (NS) physics. The tidal deformability and mass-radius relations for hybrid stars from combined hadronic and quark matter EoSs are compared for different vector couplings. We observe a significant impact of the vector mesons on the quark matter EoS such that the resulting EoS is sufficiently stiff to support two-solar-mass neutron stars.

show abstract

Section: Introductionmentioning

confidence: 74%

Section: Numerical Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Nonperturbative quark matter equations of state with vector interactions

Otto

Oertel

Schaefer

2020

Eur. Phys. J. Spec. Top.

Self Cite

View full text Add to dashboard Cite

show abstract

“…In such a scenario, not only the flow equations would be much more complicated but a two dimensional grid would have to be considered since there are two distinct chiral invariants. Following previous works [51,54], to simplify the calculations, we will neglect the possibility of pion condensation and work only with one chiral invariant. To make this approximation valid, a very small difference between quark chemical potentials of δμ = −30 MeV will be considered [60].…”

Section: The Flow Equationsmentioning

confidence: 99%

“…In this work, we will consider the 2-flavour QM model with vector interactions to explore the connection between these vector degrees of freedom with the critical region predicted by the model and the unphysical negative entropy density region. Vector interactions are very important to describe in-medium properties and are widely used to describe neutron stars [49][50][51], study the curvature of the critical line [52] and vector meson masses. The general effect of these interactions on the phase diagram, in MF calculations, is to drive the first order phase transition and CEP towards lower temperatures and higher chemical potentials.…”

Section: Introductionmentioning

confidence: 99%

Functional renormalization group study of the critical region of the quark-meson model with vector interactions

2020

View full text Add to dashboard Cite

The critical region of the two flavour quark-meson model with vector interactions is explored using the Functional Renormalization Group, a non-perturbative method that takes into account quantum and thermal fluctuations. Special attention is given to the low temperature and high density region of the phase diagram, which is very important to construct the equation of state of compact stars. As in previous studies, without repulsive vector interaction, an unphysical region of negative entropy density is found near the first order chiral phase transition. We explore the connection between this unphysical region and the chiral critical region, especially the first order line and spinodal lines, using also different values for vector interactions. We find that the unphysical negative entropy density region appears because the $$s=0$$s=0 isentropic line, near the critical region, is displaced from its $$T=0$$T=0 location. For certain values of vector interactions this region is pushed to lower temperatures and high chemical potentials in such way that the negative entropy density region on the phase diagram can even disappear. In the case of finite vector interactions, the location of the critical end point has a non-trivial behaviour in the $$T-\mu _B$$T-μB plane, which differs from that in mean field calculations.

show abstract

Exploring the physics of relativistic compact stars: an anisotropic model with quadratic equation of state in buchdahl geometry

Kumar,

Bharti

et al. 2024

Astrophys Space Sci

View full text Add to dashboard Cite

Hybrid and quark star matter based on a nonperturbative equation of state

Cited by 66 publications

References 119 publications

Nonperturbative quark matter equations of state with vector interactions

Nonperturbative quark matter equations of state with vector interactions

Functional renormalization group study of the critical region of the quark-meson model with vector interactions

Exploring the physics of relativistic compact stars: an anisotropic model with quadratic equation of state in buchdahl geometry

Contact Info

Product

Resources

About