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In this article, we attempt to find a singularity free solution of Einstein's field equations for compact stellar objects, precisely strange (quark) stars, considering Schwarzschild metric as the exterior spacetime. To this end, we consider…

广义相对论与量子宇宙学 · 物理学 2017-10-19 Debabrata Deb , Sourav Roy Chowdhury , Saibal Ray , Farook Rahaman , B. K. Guha

Parity doubling is observed in hadron states around 1.5 GeV - and the estimated energy density is found to be high. When a large excitation energy is available and the pions decouple from the quarks, the QCD interaction is still not…

高能物理 - 唯象学 · 物理学 2007-05-23 Taparati Gangopadhyay , Manjari Bagchi , Mira Dey , Jishnu Dey , Subharthi Ray

We study the temperature-dependence of the shear viscosity to entropy density ratio in pure Yang-Mills theory and in QCD with light and strange quarks within kinetic theory in the relaxation time approximation. As effective degrees of…

高能物理 - 唯象学 · 物理学 2019-08-14 Valeriya Mykhaylova , Marcus Bluhm , Krzysztof Redlich , Chihiro Sasaki

The shear viscosity $\eta$ in the van der Waals excluded volume hadron-resonance gas model is considered. For the shear viscosity the result of the non-relativistic gas of hard-core particles is extended to the mixture of particles with…

核理论 · 物理学 2011-12-06 M. I. Gorenstein , M. Hauer , O. N. Moroz

Shear viscosity is a measure of the amount of dissipation in a simple fluid. In kinetic theory shear viscosity is related to the rate of momentum transport by quasi-particles, and the uncertainty relation suggests that the ratio of shear…

高能物理 - 唯象学 · 物理学 2009-11-18 Thomas Schaefer , Derek Teaney

The remarkably small shear viscosity to entropy density ratio $\eta/s < 0.5$ of the quark-gluon plasma (QGP) is a key insight from heavy ion experiments. Nonetheless, the basic understanding of this `observable' still seems to be…

高能物理 - 唯象学 · 物理学 2018-08-15 Greg Jackson , Andre Peshier

The recent detection of gravitational waves from merging neutron star events has opened a new window on the many unknown aspects of their internal dynamics. A key role in this context is played by the transition from baryon to quark matter…

高能物理 - 唯象学 · 物理学 2019-10-08 Abha Rajan , Tyler Gorda , Simonetta Liuti , Kent Yagi

This study describes the impact of non-zero value of strange quark mass $(m_{s})$ and number density of baryons $(n)$ on the structure, stability and maximum mass of strange stars. We derive an exact relativistic solution of the Einstein…

广义相对论与量子宇宙学 · 物理学 2025-01-22 Pradip Kumar Chattopadhyay , Debadri Bhattacharjee

According to the hypothesis that strange quark matter may be the true ground state of matter at extremely high densities, strange quark stars should be stable and could exist in the Universe. It is possible that pulsars may actually be…

高能天体物理现象 · 物理学 2024-08-26 Xiao-Li Zhang , Yong-Feng Huang , Ze-Cheng Zou

This is a response to the comment, arXiv:0709.4651. It is noted that while the comment raises an extremely interesting and subtle point, the original conclusion that theoretically consistent exceptions exist for the proposed general bound…

高能物理 - 理论 · 物理学 2007-11-19 Thomas D. Cohen

It is shown that strange quark matter (SQM) objects, stars, and planets, can very efficiently convert the mechanical energy into hadronic energy when they oscillate. This is because the mass density at the edge of SQM objects,…

高能天体物理现象 · 物理学 2020-07-22 Marek Kutschera , Łukasz Bratek , Joanna Jałocha , Sebastian Kubis , Tomasz Kędziorek

Motivated by the existence of unstable modes of compact stars that eventually grow large, we study the bulk viscosity of dense matter, taking into account non-linear effects arising in the large amplitude regime, where the deviation…

核理论 · 物理学 2011-02-01 Mark G. Alford , Simin Mahmoodifar , Kai Schwenzer

One of the most striking results from the Relativistic Heavy Ion Collider is the strong elliptic flow. This review summarizes what is observed and how these results are combined with reasonable theoretical assumptions to estimate the shear…

核理论 · 物理学 2016-12-21 Derek A. Teaney

The ratio of shear viscosity ($\eta$) to entropy density ($s$) for an equilibrated system is investigated in intermediate energy heavy ion collisions below 100$A$ MeV within the framework of the Boltzmann-Uehling-Uhlenbeck (BUU) model .…

核理论 · 物理学 2011-09-01 S. X. Li , D. Q. Fang , Y. G. Ma , C. L. Zhou

In this paper, we investigate the evolution of strange quark stars (SQS) from birth as proto-strange quark stars to maturity as stable SQSs at a zero temperature. We assume that self-bound free quarks form {entirely the compact} star and…

核理论 · 物理学 2024-04-19 Adamu Issifu , Franciele M. da Silva , Débora P. Menezes

We compute the shear viscosity, $\eta$, at general temperatures $T$, in a BCS-BEC crossover scheme which is demonstrably consistent with conservation laws. The study of $\eta$ is important because it constrains microscopic theories by…

量子气体 · 物理学 2011-08-04 H. Guo , D. Wulin , C. C. Chien , K. Levin

Recent finite-temperature QCD lattice data are analyzed within a quasiparticle model, and extrapolated to nonzero chemical potential. Determined by the chiral transition temperature, the resulting equation of state of charge neutral,…

高能物理 - 唯象学 · 物理学 2007-05-23 A. Peshier , B. Kampfer , G. Soff

We perform an O(alpha_s^2) perturbative calculation of the equation of state of cold but dense QCD matter with two massless and one massive quark flavor, finding that perturbation theory converges reasonably well for quark chemical…

高能物理 - 唯象学 · 物理学 2010-06-22 Aleksi Kurkela , Paul Romatschke , Aleksi Vuorinen

The cooling of a young bare strange star is studied numerically by solving the equations of energy conservation and heat transport for both normal and superconducting strange quark matter inside the star. We show that the thermal luminosity…

天体物理学 · 物理学 2009-07-09 Dany Page , Vladimir V. Usov

Creation of strange quark stars through strong interaction deconfinement is studied based on modern estimates of hyperon formation in neutron stars. The hyperon abundance is shown to be large enough so that if strange quark matter (SQM) is…

天体物理学 · 物理学 2007-05-23 Shmuel Balberg