376 research outputs found
Dense Stellar Matter with Strange Quark Matter Driven by Kaon Condensation
The core of neutron-star matter is supposed to be at a much higher density
than the normal nuclear matter density for which various possibilities have
been suggested such as, for example, meson or hyperon condensation and/or
deconfined quark or color-superconducting matter. In this work, we explore the
implication on hadron physics of a dense compact object that has three
"phases", nuclear matter at the outer layer, kaon condensed nuclear matter in
the middle and strange quark matter at the core. Using a drastically simplified
but not unreasonable model, we develop the scenario where the different phases
are smoothly connected with the kaon condensed matter playing a role of
"doorway" to a quark core, the equation of state (EoS) of which with parameters
restricted within the range allowed by nature could be made compatible with the
mass vs. radius constraint given by the 1.97-solar mass object PSR J1614-2230
recently observed.Comment: 18 pages, 18 figure
Triple layered compact star with strange quark matter
We explore the possibility of three phases in the core of neutron star in a
form of triple layers. From the center, strange quark matter, kaon condensed
nuclear matter and nuclear matter form a triple layer. We discuss how the phase
of strange quark matter is smoothly connected to kaon condensed nuclear matter
phase. We also demonstrate that the compact star with triple layered structure
can be a model compatible with the 1.97-solar-mass object PSR J1614-2230
recently observed.Comment: 8 pages, 2 figures, to appear in the Proceedings of the Symposium on
Cosmology and Particle Astrophysics (CosPA2011), October 28-31, 2011,
Beijing, Chin
Signatures of unconventional pairing in near-vortex electronic structure of LiFeAs
A major question in Fe-based superconductors remains the structure of the
pairing, in particular whether it is of unconventional nature. The electronic
structure near vortices can serve as a platform for phase-sensitive
measurements to answer this question. By solving Bogoliubov-de Gennes equations
for LiFeAs, we calculate the energy-dependent local electronic structure near a
vortex for different nodeless gap-structure possibilities. At low energies, the
local density of states (LDOS) around a vortex is determined by the
normal-state electronic structure. However, at energies closer to the gap
value, the LDOS can distinguish an anisotropic from a conventional isotropic
s-wave gap. We show within our self-consistent calculation that in addition,
the local gap profile differs between a conventional and an unconventional
pairing. We explain this through admixing of a secondary order parameter within
Ginzburg-Landau theory. In-field scanning tunneling spectroscopy near vortices
can therefore be used as a real-space probe of the gap structure
Spectral Broadening of Radiation from Relativistic Collapsing Objects
We study light curves and the spectral broadening of the radiation emitted
during the finite interval of time by a surface of a collapsing object. We
study a simplified model of monochromatic radiations from a spherical surface
which is assumed to be falling freely. We discuss the possible way how to infer
the physical parameters, such as the mass and radii of emission, from the light
curves and spectral broadenings.Comment: 4 pages, 4 figures, Typos are corrected and substantial parts of main
text are rephrased for more better presentation. 1 reference is adde
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