14,994 research outputs found
Neutrino coupling to cosmological background: A review on gravitational Baryo/Leptogenesis
In this work we review the theories of origin of matter-antimatter asymmetry
in the Universe. The general conditions for achieving baryogenesis and
leptogenesis in a CPT conserving field theory have been laid down by Sakharov.
In this review we discuss scenarios where a background scalar or gravitational
field spontaneously breaks the CPT symmetry and splits the energy levels
between particles and anti-particles. Baryon or Lepton number violating
processes in proceeding at thermal equilibrium in such backgrounds gives rise
to Baryon or Lepton number asymmetry.Comment: 62 pages, no figures. Invited review to appear in IJMP
Energy diffusion in hard-point systems
We investigate the diffusive properties of energy fluctuations in a
one-dimensional diatomic chain of hard-point particles interacting through a
square--well potential. The evolution of initially localized infinitesimal and
finite perturbations is numerically investigated for different density values.
All cases belong to the same universality class which can be also interpreted
as a Levy walk of the energy with scaling exponent 3/5. The zero-pressure limit
is nevertheless exceptional in that normal diffusion is found in tangent space
and yet anomalous diffusion with a different rate for perturbations of finite
amplitude. The different behaviour of the two classes of perturbations is
traced back to the "stable chaos" type of dynamics exhibited by this model.
Finally, the effect of an additional internal degree of freedom is
investigated, finding that it does not modify the overall scenarioComment: 16 pages, 15 figure
Design and fabrication of a data logger for atmospheric pressure, temperature and relative humidity for gas-filled detector development
A novel instrument has been developed to monitor and record the ambient pa-
rameters such as temperature, atmospheric pressure and relative humidity. These
parameters are very essential for understanding the characteristics such as
gain of gas filled detectors like Gas Electron Multiplier (GEM) and Multi Wire
Propor- tional Counter (MWPC). In this article the details of the design,
fabrication and operation processes of the device has been presented.Comment: 11 pages, 12 figure
How Many Templates for GW Chirp Detection? The Minimal-Match Issue Revisited
In a recent paper dealing with maximum likelihood detection of gravitational
wave chirps from coalescing binaries with unknown parameters we introduced an
accurate representation of the no-signal cumulative distribution of the
supremum of the whole correlator bank. This result can be used to derive a
refined estimate of the number of templates yielding the best tradeoff between
detector's performance (in terms of lost signals among those potentially
detectable) and computational burden.Comment: submitted to Class. Quantum Grav. Typing error in eq. (4.8) fixed;
figure replaced in version
Search algorithm for a gravitational wave signal in association with Gamma Ray Burst GRB030329 using the LIGO detectors
One of the brightest Gamma Ray Burst ever recorded, GRB030329, occurred
during the second science run of the LIGO detectors. At that time, both
interferometers at the Hanford, WA LIGO site were in lock and acquiring data.
The data collected from the two Hanford detectors was analyzed for the presence
of a gravitational wave signal associated with this GRB. This paper presents a
detailed description of the search algorithm implemented in the current
analysis.Comment: To appear in the Proceedings of 8th Gravitational Wave Data Analysis
Workshop (Milwaukee, WI) (Class. Quantum Grav.
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