Related papers: Can very compact and very massive neutron stars bo…
Using the idea of a smooth crossover from the hadronic matter with hyperons to quark matter with strangeness, we show that the maximum mass of neutron stars with quark matter core can be larger than those without quark matter core. This is…
We summarize our current knowledge of neutron star masses and radii. Recent instrumentation and computational advances have resulted in a rapid increase in the discovery rate and precise timing of radio pulsars in binaries in the last few…
(Abridged) The recent measurement of the mass of two $2\, M_\odot$ pulsars has raised the question whether such large masses allow for the existence of exotic degrees of freedom, such as hyperons, inside neutron stars. In the present work…
Astrophysicists distinguish between three different types of compact stars. These are white dwarfs, neutron stars, and black holes. The former contain matter in one of the densest forms found in the Universe which, together with the…
We present in this article an overview of the problem of neutron star masses. After a brief appraisal of the methods employed to determine the masses of neutron stars in binary systems, the existing sample of measured masses is presented,…
It is usually thought that a single equation of state (EoS) model "correctly" represents cores of all compact stars. Here we emphasize that two families of compact stars, viz., neutron stars and strange stars, can coexist in nature, and…
Neutron star properties depend on both nuclear physics and astrophysical processes, and thus observations of neutron stars offer constraints on both large-scale astrophysics and the behavior of cold, dense matter. In this study, we use…
We describe distinctive stellar features indicating the presence of hyperons in neutron stars as compared to purely nucleonic systems. A strongly negative curvature of the mass-radius relation $R(M)$ is characteristic of hyperons, which can…
Simultaneous measurement of mass and radius with high precision is essential to unravel the equation of state of matter at the centre of neutron stars. Measurement of massive pulsars indicates that the equation of state has to be stiff at…
We study how the $\Lambda$ hyperon threshold influences the radius of the canonical $1.4 ~M_\odot$ neutron star in the light of the measurements found in the recent literature. We show that the onset of a new degree of freedom not only…
We demonstrate that future radius measurement of the NICER mission have the potential to reveal the existence of a strong phase transition in dense neutron star matter by confirming the existence of so called twin stars, compact star…
The properties of dense hadronic and quark matter and its relation to compact stars are discussed. In a bottom-up approach one starts with nuclear and hypernuclear physics at low density and extrapolates hadronic matter to large densities.…
We investigate the quantum hadrodynamic equation of state for neutron stars (with and without including hyperons) in the presence of strong magnetic fields. The deduced masses and radii are consistent with recent observations of high mass…
This short review aims at giving a brief overview of the various states of matter that have been suggested to exist in the ultra-dense centers of neutron stars. Particular emphasis is put on the role of quark deconfinement in neutron stars…
We combine equation of state of dense matter up to twice nuclear saturation density ($n_{\rm sat}=0.16\, \text{fm}^{-3}$) obtained using chiral effective field theory ($\chi$EFT), and recent observations of neutron stars to gain insights…
Since the discovery of neutron stars with masses around 2 solar masses the composition of matter in the central part of these massive stars has been intensively discussed. Within this paper we will (re)investigate the question of the…
Strange quark matter in beta equilibrium at high densities is studied in a quark confinement model. Two equations of state are dynamically generated for the {\it same} set of model parameters used to describe the nucleon: one corresponds to…
The properties of neutron stars are determined by the nature of the matter that they contain. These properties can be constrained by measurements of the star's size. We obtain stringent constraints on neutron-star radii by combining…
Analyses for the NICER data indicate that there is no significant variation of the compact star radii within the mass range of 1.4 to 2.0 solar masses. Yamamoto et al. [Phys. Rev. C 108, 035811 (2023)] concluded recently that ``this feature…
I have demonstrated the existence of a tight correlation between the mass, radius, central density, and pressure of maximum-mass neutron stars modeled using diverse baryonic equations of state. A possible explanation for these correlations…