scholarly journals Relativistic Cowling approximation for fluid oscillation modes of color superconducting self-bound stars

2012 ◽  
Vol 8 (S291) ◽  
pp. 451-451
Author(s):  
German Lugones ◽  
Cesar Vasquez Flores
Keyword(s):  
Equation Of State ◽  
Gravitational Waves ◽  
Internal Structure ◽  
Quark Matter ◽  
Normal Modes ◽  
Pressure Oscillation ◽  
Compact Stars ◽  
Color Superconductivity ◽  
Strange Stars ◽  
Oscillation Modes

AbstractThe investigation of the quasi-normal modes of oscillation of compact stars can reveal much information about their equation of state and internal structure mainly through the analysis of the expected emission of gravitational waves. In this work we study non-radial oscillation modes of strange stars consisting of color superconducting quark matter. We focus on the fundamental and pressure oscillation modes within the frame of the Cowling approximation. We discuss the observable features that may allow a differentiation among hadronic stars, strange stars, and strange stars with color superconductivity.

SELF-LENSING EFFECTS FOR COMPACT STARS AND THEIR MASS–RADIUS RELATION

2004 ◽  
Vol 19 (32) ◽  
pp. 2431-2435
Author(s):  
A. R. PRASANNA ◽  
SUBHARTHI RAY
Keyword(s):  
General Relativity ◽  
Neutron Star ◽  
Equation Of State ◽  
Quark Matter ◽  
Strange Quark ◽  
Strange Quark Matter ◽  
Compact Stars ◽  
Strange Stars ◽  
Lensing Effect ◽  
R Relation

During the last couple of years astronomers and astrophysicists have been debating on the fact whether the so-called "strange stars" — stars made up of strange quark matter, have been discovered with the candidates like SAX J1808.4–3658, 4U 1728–34, RX J1856.5–3754, etc. The main contention has been the estimation of radius of the star for an assumed mass of ~ 1.4 M⊙ and to see whether the point overlaps with the graphs for the neutron star equation of state or whether it goes to the region of stars made of strange matter equation of state. Using the well-established formulae from general relativity for the gravitational redshift and the "lensing effect" due to bending of photon trajectories, we, in this letter, relate the parameters M and R with the observable parameters, the redshift z and the radiation radius R∞, thus constraining both M and R for specific ranges, without any other arbitrariness. With the required inputs from observations, one ought to incorporate the effects of self-lensing of the compact stars which has been otherwise ignored in all of the estimations done so far. Nonetheless, these effects of self-lensing make a marked difference for constraints on the M–R relation.

scholarly journals Quadrupole moments of rotating compact stars

2012 ◽  
Vol 8 (S291) ◽  
pp. 536-536
Author(s):  
Martin Urbanec ◽  
John Miller ◽  
Zdenek Stuchlik
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Neutron Stars ◽  
Strange Star ◽  
Compact Stars ◽  
Quadrupole Moments ◽  
Strange Stars

AbstractWe present quadrupole moments of rotating neutron and strange stars calculated using standard Hartle Thorne approach. We demonstrate differences between neutron and strange star parameters connected with quadrupole moments and how this parameters could be, in the case of neutron stars, approximated almost independently on neutron star equation of state.

NEW ASPECTS ON GRAVITATIONAL WAVE EMISSION BY NEUTRON STARS

2004 ◽  
Vol 13 (07) ◽  
pp. 1293-1296 ◽  
Author(s):  
GUILHERME F. MARRANGHELLO ◽  
CÉSAR A. Z. VASCONCELLOS ◽  
JOSÉ A. de FREITAS PACHECO ◽  
MANFRED DILLIG ◽  
HÉLIO T. COELHO
Keyword(s):  
Phase Transition ◽  
Equation Of State ◽  
Neutron Stars ◽  
Nuclear Matter ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Quark Matter ◽  
Inner Core ◽  
Compact Objects ◽  
Wave Emission

We discuss, in this work, new aspects related to the emission of gravitational waves by neutron stars, which undergo a phase transition, from nuclear to quark matter, in its inner core. Such a phase transition would liberate around 1052–53 erg of energy in the form of gravitational waves which, if detected, may shed some light in the structure of these compact objects and provide new insights on the equation of state of nuclear matter.

scholarly journals NEUTRON STAR MATTER EQUATION OF STATE AND GRAVITATIONAL WAVE EMISSION

2005 ◽  
Vol 20 (31) ◽  
pp. 2335-2349 ◽  
Author(s):  
OMAR BENHAR
Keyword(s):  
Experimental Study ◽  
Neutron Star ◽  
Equation Of State ◽  
Neutron Stars ◽  
Gravitational Waves ◽  
Neutron Star Matter ◽  
Oscillation Modes ◽  
Nonradial Oscillation ◽  
Macroscopic Objects ◽  
Wave Emission

The EOS of strongly interacting matter at densities ten to fifteen orders of magnitude larger than the typical density of terrestrial macroscopic objects determines a number of neutron star properties, including the pattern of gravitational waves emitted following the excitation of nonradial oscillation modes. This paper reviews some of the approaches employed to model neutron star matter, as well as the prospects for obtaining new insights from the experimental study of gravitational waves emitted by neutron stars.

scholarly journals Gravitational-Wave Asteroseismology as a Tool to Reveal the Equation of State of Relativistic Neutron Stars

2002 ◽  
Vol 185 ◽  
pp. 612-615
Author(s):  
Johannes Ruoff
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Neutron Stars ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Oscillation Modes

AbstractThe equation of state (EOS) is still the big unknown in the physics of neutron stars. An accurate measurement of both the mass and the radius of a neutron star would put severe constraints on the range of possible EOSs. I discuss how the parameters of the oscillation modes of a neutron star, measured from the emitted gravitational waves, can in principle be used to infer its mass and radius, and thus reveal its EOS.

RADIAL OSCILLATIONS OF COLOR SUPERCONDUCTING QUARK STARS

2010 ◽  
Vol 19 (08n10) ◽  
pp. 1499-1504 ◽  
Author(s):  
C. VASQUEZ FLORES ◽  
G. LUGONES
Keyword(s):  
Quark Matter ◽  
Stellar Structure ◽  
Color Superconductivity ◽  
Quark Stars ◽  
Equilibrium Configurations ◽  
Oscillation Modes

In this work, we investigate the effect of color superconductivity in adiabatic radial oscillations of stars consisting of quark matter. We calculate the equilibrium configurations by integrating the Tolman–Oppenheimer–Volkoff equations of relativistic stellar structure and then we integrate the equations of relativistic radial oscillations to determine the oscillation modes.

scholarly journals CAN COLD QUARK MATTER BE SOLID?

2010 ◽  
Vol 19 (08n10) ◽  
pp. 1437-1446 ◽  
Author(s):  
R. XU
Keyword(s):  
Solid State ◽  
Interaction Energy ◽  
Ground State ◽  
Quark Matter ◽  
Fermi Gas ◽  
The State ◽  
Compact Stars ◽  
Color Superconductivity ◽  
Many Body ◽  
Coupling Treatment

The state of cold quark matter challenges both astrophysicists and particle physicists, and even many-body physicists. It is conventionally suggested that BCS-like color superconductivity occurs in cold quark matter; however, other scenarios with a ground state rather than of Fermi gas could still be possible. It is addressed that quarks are dressed and clustered in cold quark matter at realistic baryon densities of compact stars, since a weakly coupling treatment of the interaction between constituent quarks would not be reliable. Cold quark matter is conjectured to be in a solid state if thermal kinematic energy is much lower than the interaction energy of quark clusters, and such a state could be relevant to different manifestations of pulsar-like compact stars.

scholarly journals Some New Models of Strange Stars in 5-D Einstein-Gauss-Bonnet Gravity

2021 ◽  
Author(s):  
Manuel Malaver ◽  
Hamed Daei Kasmaei
Keyword(s):  
Equation Of State ◽  
Energy Density ◽  
Nonlinear Equation ◽  
Radial Pressure ◽  
Compact Stars ◽  
Coupling Constant ◽  
Strange Stars ◽  
Bonnet Gravity ◽  
New Models ◽  
Linear And Nonlinear

In this paper, we present some new models for anisotropic compact stars within the framework of 5-dimensional Einstein-Gauss-Bonnet (EGB) gravity with a linear and nonlinear equation of state considering a metric potential proposed for Thirukkanesh and Ragel (2012) and generalized for Malaver (2014). The new obtained models satisfy all physical requirements of a physically reasonable stellar object. Variables as energy density, radial pressure and the anisotropy are dependent of the values of the Gauss-Bonnet coupling constant

Sign in / Sign up

Export Citation Format

Share Document