28,860 research outputs found
Strange stars at finite temperature
We calculate strange star properties, using large N_c approximation with
built-in chiral symmetry restoration (CSM). We used a relativistic Hartree Fock
mean field approximation method, using a modified Richardson potential with two
scale parameters \Lambda and \Lambda^\prime, to find a new set of equation of
states for strange quark matter. We take the effect of temperature (T) on gluon
mass, in addition to the usual density dependence, and find that the transition
T from hadronic matter to strange matter is 80 MeV. Therefore formation of
strange stars may be the only signal for formation of QGP with asymptotic
freedom and CSM.Comment: To be published in the proceedings of The Third 21COE Symposium, held
at Department of Physics, Waseda University, Tokyo, Japan, September 1-3,
200
Does monetary policy have differential state-level effects? an empirical evaluation
The paper examines whether monetary policy has similar effects across major states in the Indian polity. Impulse response functions from an estimated Structural Vector Auto Regression (SVAR) reveal two sets of states: a core of states that respond to monetary policy in a significant fashion vis-Ã -vis others whose response is less significant. The paper attempts to trace the reasons for the differential response of these two sets of states in terms of financial deepening and differential industry mix.monetary policy; regional effect; optimum currency area
The Formal Underpinnings of the Response Functions used in X-Ray Spectral Analysis
This work provides an in-depth mathematical description of the response
functions that are used for spatial and spectral analysis of X-ray data. The
use of such functions is well-known to anyone familiar with the analysis of
X-ray data where they may be identified with the quantities contained in the
Ancillary Response File (ARF), the Redistribution Matrix File (RMF), and the
Exposure Map. Starting from first-principles, explicit mathematical expressions
for these functions, for both imaging and dispersive modes, are arrived at in
terms of the underlying instrumental characteristics of the telescope including
the effects of pointing motion. The response functions are presented in the
context of integral equations relating the expected detector count rate to the
source spectrum incident upon the telescope. Their application to the analysis
of several source distributions is considered. These include multiple, possibly
overlapping, and spectrally distinct point sources, as well as extended
sources. Assumptions and limitations behind the usage of these functions, as
well as their practical computation are addressed.Comment: 22 pages, 3 figures (LaTeX
On the Influence of Stochastic Moments in the Solution of the Neutron Point Kinetics Equation
On the Influence of Stochastic Moments in the Solution of the Neutron Point
Kinetics EquationComment: 12 pages, 2 figure
HST Observations of Gravitationally Lensed Features in the Rich Cluster Ac114
Deep Hubble Space Telescope images of superlative resolution obtained for the
distant rich cluster AC114 (z=0.31) reveal a variety of gravitational lensing
phenomena for which ground-based spectroscopy is available. We present a
luminous arc which is clearly resolved by HST and appears to be a lensed z=0.64
sub-L star spiral galaxy with a detected rotation curve. Of greatest interest
is a remarkably symmetrical pair of compact blue images separated by 10 arcsec
and lying close to the cluster cD. We propose that these images arise from a
single very faint background source gravitationally lensed by the cluster core.
Deep ground-based spectroscopy confirms the lensing hypothesis and suggests the
source is a compact star forming system at a redshift z=1.86. Taking advantage
of the resolved structure around each image and their very blue colours, we
have identified a candidate third image of the same source roughly 50 arcsec
away. The angular separation of the three images is much larger than previous
multiply-imaged systems and indicates a deep gravitational potential in the
cluster centre. Resolved multiply-imaged systems, readily recognised with HST,
promise to provide unique constraints on the mass distribution in the cores of
intermediate redshift clusters.Comment: submitted to ApJ, 6 pages (no figures), uuencoded Postscript,
compressed TAR of Postscript figures available via anonymous ftp in
users/irs/figs/ac114_figs.tar.gz on astro.caltech.edu. PAL-IRS-
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