Related papers: Conformality and percolation threshold in neutron …
Generating an ensemble of equations of state that fulfill multimessenger constraints, we statistically determine the properties of dense matter found inside neutron stars (NSs). We calculate the speed of sound and trace anomaly and…
We discuss an interpretation that a peak in the sound velocity in neutron star matter, as suggested by the observational data, signifies strongly-coupled conformal matter. The normalized trace anomaly is a dimensionless measure of…
Matter properties at the intermediate densities are still unknown to us. In this work, we use a neural network approach to study matter at intermediate densities to analyze the variation of the speed of sound and the measure of trace…
The structure of the dense-matter equation of state is essential for the phenomenology of neutron stars. In this work, I relate the thermodynamic properties to the average speed of sound in the interior of a star. I study the consequences…
At the supranuclear densities achieved inside a neutron star, matter may exhibit extreme properties. In particular, it may be the case that a suitable average of the speed of sound squared exceeds the so-called conformal limit, i.e.,…
The effects of the presence of hyperons and a phase transition to deconfined quark matter on the speed of sound in neutron stars is investigated. For this purpose a composite description consisting of a model of the covariant field theory…
We present the argument that "pseudo-conformal" symmetry permeates from low density near nuclear matter to high density in the core of massive neutron stars. As a support of this argument, we describe how the quenched $g_A\approx 1$ in…
The speed of sound is a novel probe of equation of state and phase transitions in dense cores of neutron stars. Recently nuclear experiments extracted a surprising thick neutron skin of $^{208}$Pb, causing tensions to reproduce the tidal…
Neutron stars (NSs) serve as laboratories for probing strongly interacting matter at the most extreme densities. Their inner cores are expected to be dense enough to host deconfined quark matter. Utilizing state-of-the-art theoretical and…
The accurate determination of the maximum mass of the neutron stars is one of the most important tasks in astrophysics. It is directly related to the identification of the black holes in the universe, the production of neutron stars from…
The historic first detection of the binary neutron star merger GW170817 by the LIGO-Virgo collaboration has set a limit on the gravitational deformability of neutron stars. In contrast, radio observations of PSR J0740+6620 find a very…
The upper bound of the speed of sound in dense nuclear matter is one of the most interesting but still unsolved problems in Nuclear Physics. Theoretical studies in connection with recent observational data of isolated neutron stars as well…
This presentation in two parts starts with a brief review on the speed of sound in neutron star matter as inferred from observational data. It is pointed out that, in view the strong constraints imposed by observed properties of the…
We introduce a parametrized density-dependent speed of sound and construct an ensemble of equations of state for neutron stars which are found to closely resemble the realistic equations of state calculated using relativistic mean field…
Information on the phase structure of strongly interacting matter at high baryon densities can be gained from observations of neutron stars and their detailed analysis. In the present work Bayesian inference methods are used to set…
We show that the existence of massive neutron stars and asymptotic freedom of QCD place robust upper bounds on the lowest sound speed of the ultra-dense matter unattainable in neutron stars. Centered on worst-case scenarios, our limits are…
The dense-matter equation of state (EOS) under neutron-star conditions is investigated. We focus on the qualitative behavior of the speed of sound and its average. We characterize and compare the theoretical criteria for identifying nearly…
It has been suggested in the literature that the sound velocity of the nuclear matter $v_s$ violates the so-called sound velocity bound $v_s \le c/\sqrt{3}$ at high density, where $c$ is the speed of light. In this paper, we revisit this…
The existence of massive compact stars $(M\gtrsim 2.1 M_{\odot})$ implies that the conformal limit of the speed of sound $c_s^2=1/3$ is violated if those stars have a crust of ordinary nuclear matter. Here we show that, if the most massive…
The observation of maximally rotating neutron stars (in comparison to nonrotating ones) may provide more information on the behavior of nuclear matter at high densities. We provide a theoretical treatment concerning the effects of the upper…