Conveners
Parallels Track F: Monday I
- Andreas Schmitt (University of Southampton)
Parallels Track F: Monday II
- Andreas Schmitt (University of Southampton)
Parallels Track F: Tuesday I
- Johann Marton (Austrian Academy of Sciences, Stefan Meyer Institute)
Parallels Track F: Tuesday II
- Johann Marton (Austrian Academy of Sciences, Stefan Meyer Institute)
Parallels Track F: Thursday I
- David Blaschke (University of Wroclaw)
Parallels Track F: Thursday II
- David Blaschke (University of Wroclaw)
Parallels Track F: Friday I
- Laura Tolos (ICE & University of Stavanger)
Parallels Track F: Friday II
- Laura Tolos (ICE & University of Stavanger)
Determining the phase structure of Quantum Chromodynamics (QCD) and its Equation of State (EoS) at densities and temperatures realised inside neutron stars and their mergers is a long-standing open problem.
I will present a framework for the EoS of dense and hot QCD that describes the deconfinement phase transition between a dense baryonic and quark matter phase via the holographic V-QCD...
Description of nuclear matter in the core of neutron stars eludes the main tools of investigation of QCD, such as perturbation theory and the lattice formulation of the theory. Recently, the application of the holographic paradigm (both via top-down and bottom-up models) to this task has led to many encouraging results, both qualitatively and quantitatively. In this talk, I will present our...
I will discuss the recent description of realistic neutron stars using a model derived from holography in [2111.03374,2112.10633]. After a brief review of beta-equilibrated isospin-asymmetric dense holographic baryonic matter within the Sakai-Sugimoto model, I will discuss how the resulting equation of state is used for constructing the full compact star within a single framework with only two...
Cold and dense matter can be explored in a systematic way both in the high-density (perturbative QCD) and low-density (Chiral EFT) regime. However, the path connecting them is yet to be discovered. As a result, these descriptions are usually extrapolated into the intermediate density regime and then connected at some transition point. In this work I will present a model that has features of...
Lattice methods are spectacularly successful in measuring thermodynamic properties of strongly interacting matter described by Quantum Chromodynamics (QCD) at small baryon densities, however the existing lattice techniques cannot be easily extended to large densities due to the infamous "sign problem". In this work we have studied the hadronic phase of QCD using relativistic nuclear mean...
The possible existence of hybrid stars is studied using several multi-quark interaction channels. The hadronic phase consists of an EOS with presently accepted nuclear matter properties and the quark model constrained by the vacuum properties of several light mesons. The dependence of several NS properties on the different quark interactions is analyzed. We show that the present constraints...
In this talk, I will discuss the phase diagram at finite isospin density using
two and three flavor chiral perturbation theory. I will also discuss the quark and pion condensates in the pion-condensed phase at T=0. Moreover, the pion-condensed phase has many interesting properties. At small chemical potentials, the system behaves as a dilute nonrelativistic Bose gas with an effective s-wave...
Chiral perturbation theory in the presence of the chiral anomaly predicts a so-called chiral soliton lattice in the presence of a magnetic field and a baryon chemical potential. This phase becomes unstable with respect to charged pion condensation if the magnetic field is further increased. I will point out that this instability bears a striking resemblance to the well-known instability at the...
[Reality of the Crosssover Scenarios]
Because the ab-initio EOSs from the $\chi$EFT and the pQCD are both soft, it is unlikely to have a 1st-order phase transition to quark matter that would make the EOS even softer. These calculations as well as observational data and discussions of quark-hadron continuity / quarkyonic matter support the scenario of smooth and continuous realization of...
We outline the role that an early deconfinement phase transition from normal nuclear matter to a color superconducting quark-gluon plasma phase plays for the phenomenology of supernova explosions and binary neutron star mergers. To this end we extend the compact star equation of state (EoS) from vanishing to moderately high temperatures that become accessible in the CBM experiment at FAIR. We...
Black hole–neutron star mergers (BHNS) are astrophysical phenomena of great interest because they not only produce gravitational-wave signals but also can have very energetic electromagnetic counterparts in particular in the form of kilonova explosions. The disruption of the neutron star produces the dynamical ejection of some material and the formation of a disk of hot matter around the black...
The fundamental constituent of matter at high temperature and density has intrigued physicists for quite some time. Recent results from heavy-ion colliders have enriched the Quantum Chromodynamics (QCD) phase diagram at high temperature and low baryon density. However, the phase at low temperature and finite (mostly intermediate) baryon density remain unexplored. Theoretical QCD calculation...
We analyze the recent astrophysical constraints in the context of a hadronic equation of state (EoS) in which the baryonic matter is subject to chiral symmetry restoration. We show that with such EoS it is possible to reconcile the modern constraints on the neutron star (NS) mass, radius, and tidal deformability (TD). We find that the softening of the EoS, required by the TD constraint of a...
Abstract: Formed in the aftermath of gravitational core-collapse supernova explosions, neutron stars are the most compact observed stars. Their average density exceeds that found inside the heaviest atomic nuclei. According to our current understanding, a neutron star is stratified into distinct layers. The surface is probably covered by a metallic ocean. The solid layers beneath consist of a...
The FSU2H equation of state model, originally developed to describe cold neutron star matter with hyperonic cores, is extended to finite temperature [1]. Results are presented for a wide range of temperatures and lepton fractions, which cover the conditionsmet in protoneutron star matter, neutron star mergers and supernova explosions. It is found that the temperature effects on...
We consider kinetic coefficients (thermal conductivity, shear viscosity, momentum transfer rates) of the magnetized neutron star cores within the framework of the Landau Fermi-liquid theory. We restrict ourselves to the case of normal (i.e. non-superfluid) matter and nucleonic composition. The magnetic field is taken to be non-quantizing. The presence of magnetic field leads to the tensor...
The trace anomaly is a quantity of fundamental interest in field theories, which signals whether the underlying theory is conformal. In the context of neutron stars, we propose the trace anomaly for a new measure of the conformality as an alternative to the speed of sound; here we specifically consider the normalized trace anomaly, $1/3 - P/\varepsilon$, with $P$ and $\varepsilon$ being the...
I discuss the recent progress in state-of-the art perturbative QCD calculations of the equation of state at large chemical potential. I describe why these calculations that are reliable at asymptotically high densities constrain the equation of state at neutron star densities, and describe how the theoretical calculations can be confronted with multimessenger observations to empirically...
At asymptotically high densities, the neutron-star-matter equation of state (EOS) must approach the EOS of beta-equilibrated QCD matter, as calculated directly within the fundamental QCD theory. This nontrivial constraint at high density, pressure, and chemical potential impacts the inference of the neutron-star-matter EOS at even lower densities. In this talk, I show how this constraint...
We present a systematic investigation of the possible locations for the special point (SP), a unique feature of hybrid neutron stars in the mass-radius. The study is performed within the two-phase approach where the high-density (quark matter) phase is described by the constant-sound-speed (CSS) equation of state (EoS) and the nuclear matter phase around saturation density is varied from very...
We study the impact of asymmetric fermionic and bosonic dark matter on neutron star properties, including tidal deformability, maximum masses, radii, etc. The conditions at which dark matter particles tend to condensate in the core of the star or create an extended halo are presented. We show that dark matter condensed in a core leads to a decrease of the total gravitational mass and tidal...
More than 20 years ago, Glendenning et al. (1995) proposed the existence of stable white dwarfs with a core of strange quark matter. More recently, by studying radial modes, Alford et al. (2017) concluded that those objects are unstable. We investigate again the stability of these objects by looking at their radial oscillations, and we assume that there is no phase transition between hadronic...
Charge radii of the light nuclei depend on the charge distributions of the proton and the neutron and on the nuclear structure --- the way how nucleons are distributed inside the nucleus. We present a high-accuracy calculation of the nuclear structure for A=2,3,4 nuclei using the latest two- and three-nucleon forces and charge density operators derived up through the fifth order in the chiral...
There is presently no consensus on how the $\phi$ meson mass and width will change once it is put in a dense environment such as nuclear matter. While many theoretical works exist, connecting them with experimental measurements remains non-trivial task, as the $\phi$ meson in nuclear matter is usually produced in relatively high-energy pA reactions, which are generally non-equilibrium...
With the detection of compact binary coalescences and their
electromagnetic counterparts by gravitational-wave detectors, a new
era of multi-messenger astronomy has begun. In this talk, I will
describe how GW170817, our first example in this new class, is being
used to constrain the unknown equation of state of cold supranuclear
matter, and to measure the Hubble constant. I will then...
Thermal production of sexaquarks are calculated in different Statistical Models.
Sexaquarks are a hypothetical low mass, small radius uuddss dibaryon which has been proposed recently and especially as a candidate for Dark Matter [1,2]. The low mass region below 2 GeV escapes upper limits set
from experiments which have searched for the unstable, higher mass H-dibaryon and did not find...
We present steps towards a consistent synthesis of nuclear observables such as neutron skins, dipole polarizabilities and nuclear masses, and neutron star observables such as radii and tidal deformabilities. Our models are parameterized by five independent variables: the first three parameters in the density expansion of the symmetry energy and two indices for the polytropic equations of state...
