9,803 research outputs found
Accretion mode changes in Centaurus X-3
We report here discovery of the existence of two different accretion modes in
the high mass X-ray binary pulsar Cen X-3 during its high states. The multiband
X-ray light curves of Cen X-3 lasting for more than 3400 days obtained with the
All Sky Monitor (ASM) onboard the Rossi X-ray Timing Explorer (RXTE) shows many
episodes of high and low X-ray intensities. The high intensity phases last
between a few to upto 110 days and the separation between two high intensity
phases also varies widely. One remarkable feature deduced from the RXTE-ASM
light curves is that during these high intensity phases, Cen X-3 manifests in
two very distinct spectral states. When the source makes a transition from the
low intensity phase to the high intensity phase, it adopts one of these two
spectral states and during the entire high intensity phase remains in that
particular spectral state. During December 2000 to April 2004, all the high
intensity episodes showed a hardness ratio which is significantly larger than
the same during all the high states prior to and subsequent to this period. It
is also found that most of the soft outbursts reach a nearly constant peak flux
in the 5--12 keV band. For comparison, similar analysis was carried out on the
long term X-ray light curves of three other X-ray binary pulsars Her X-1, Vela
X-1, and SMC X-1. Results obtained with these sources are also presented here
and we found that none of the other sources show such a behaviour. From these
observations, we suggest that Cen X-3 has two different accretion modes and in
the course of nine years it has exhibited two switch overs between these.Comment: 5 pages, 5 postscript figures, accepted for publication in Astronomy
and Astrophysics Letter
Eigenvalue distribution of the Dirac operator at finite temperature with (2+1)-flavor dynamical quarks using the HISQ action
We report on the behavior of the eigenvalue distribution of the Dirac
operator in (2+1)-flavor QCD at finite temperature, using the HISQ action. We
calculate the eigenvalue density at several values of the temperature close to
the pseudocritical temperature. For this study we use gauge field
configurations generated on lattices of size with two light
quark masses corresponding to pion masses of about 160 and 115 MeV. We find
that the eigenvalue density below receives large contributions from
near-zero modes which become smaller as the temperature increases or the light
quark mass decreases. Moreover we find no clear evidence for a gap in the
eigenvalue density up to 1.1. We also analyze the eigenvalue density near
where it appears to show a power-law behavior consistent with what is
expected in the critical region near the second order chiral symmetry restoring
phase transition in the massless limit.Comment: 7 pages, 7 figures, talk presented at the XXIX International
Symposium on Lattice Field Theory, July 10-16 2011, Squaw Valley, Lake Tahoe,
California, US
Noise In Nonohmic Regimes Of Disordered Systems
We present here a short review of mainly experimental properties of noise as
disordered systems are driven into non-ohmic regimes by applying voltages of
few volts only. It is found that the noise does not simply follow the
resistance in that the direction of change of noise could be opposite to that
of resistance. It is discussed how this and other properties make the noise a
complementary and incisive tool for studying complex systems, particularly its
dynamic properties. Study of noise in non-ohmic regimes in physical systems is
rather in a nascent stage. Some of the open issues are highlighted.Comment: 9 Pages, 7 figures. Reported in Unsolved Problems of Noise and
Fluctuations: UPoN 2005, Gallipoli, Italy, June 6-10, 200
Revolution and the Maoists
In October 2015, in one of the most talked about legislative polls in the eastern Indian province of Bihar, an estimated 55 per cent of the electorate cast their votes in 32 constituencies across the six Maoist-affected districts. The entire elections passed off peacefully. Interestingly, the polling also saw more women voters turning out than just their male counterparts.
In fact, Bihar has been witness to the growth of the Maoist Movement in the Eastern sector – right from its inception in the late 1960s and early 1970s, through the gory years of the upper-caste financed days of private militias like Ranvir Sena and the Sunlight Sena and later in the post-2004 Maoist avatar of the erstwhile Naxalite Movement. Be it the land struggles of Mushahari in mid-1968 or the audacious Jehanabad jailbreak incident towards the end of 2005, [undivided] Bihar has seen and knows it all. There were districts and rural areas, until recently, in which the writ of the Maoists was the ‘rule of law'.
DOI: 10.5281/zenodo.336690
Precise Variational Calculation For The Doubly Excited State (2p^2)^3P^e of Helium
Highly precise variational calculations of non-relativistic energies of the
(2p^2)^3P^e state of Helium atom are presented.We get an upper bound energy
E=-0.71050015565678 a.u.,the lowest yet obtained.Comment: 5 pages, 1 tabl
Topological Defects in the Left-Right Symmetric Model and their Relevance to Cosmology
It is shown that the minimal left-right symmetric model admits cosmic string
and domain wall solutions. The cosmic strings arise when the SU(2)_R is broken
and can either be destabilized at the electroweak scale or remain stable
through the subsequent breakdown to U(1)_{EM}. The strings carry zero modes of
the neutrino fields. Two distinct domain wall configurations exist above the
electroweak phase transition and disappear after that. Thier destablization
provides new sources of non-equilibrium effects below the electroweak scale
which is relevant to baryogenesis.Comment: 29 pages, LaTex file with 6 postscript figure
Empirical Analysis of an Augmented Schumpeterian Endogenous Growth Model
This study conducts an empirical analysis of an augmented Schumpeterian endogenous growth theory using aggregate-level data from 1981 to 2017 for 31 OECD countries. Despite a considerable number of studies analysing endogenous growth, cross-country analyses utilising estimators robust to endogeneity-bias and controlling for the macroeconomic effect of institutions are still rare. In this paper, we employ a relatively consistent estimator to analyse an augmented neoclassical production function that links output per worker to capital accumulation, technological progress, and institutions. Our results from the extended system of generalised method of momentS estimation align with the mainstream consensus that capital accumulation and technological progress or innovation, in the form of R&D activities, determine the level of output per worker in the long run. But in addition, we find that effective institutions underlie the innovation effect. On average, the impact of R&D activities on output per worker is higher in countries with more effective institutions
Does Increasing Product Complexity and Diversity Cause Economic Growth in the Long-Run? A GMM Panel VAR Evidence
Using aggregate data from 31 Organization for Economic Co-operation and Development (OECD) countries covering periods from 1982 to 2017, this study examines the notion that the level of product complexity is a good determinant of economic growth in the long run. We use the impulse-response function (IRF) computed from the consistent generalized method of moment panel vector autoregressive (GMM pVAR) model to estimate the response of the real output growth to a change in the economic complexity index. The IRF shows that the economic complexity index has a significant impact on economic growth; a 1 standard deviation shock to the economic complexity index at time 0 contributes around 2.34 percentage points to the average rate of growth of output within the first period. The point estimates are positive and significant up to the third period. The cumulative IRF shows that the aggregate impact on economic growth is about 4.4% in the long run. Compared to some widely used innovation proxies such as the gross expenditure on research and development and secondary school enrollment, the economic complexity index performs relatively better in our model in determining economic growth in the long run
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