20,179 research outputs found
On the asymmetric zero-range in the rarefaction fan
We consider the one-dimensional asymmetric zero-range process starting from a
step decreasing profile. In the hydrodynamic limit this initial condition leads
to the rarefaction fan of the associated hydrodynamic equation. Under this
initial condition and for totally asymmetric jumps, we show that the weighted
sum of joint probabilities for second class particles sharing the same site is
convergent and we compute its limit. For partially asymmetric jumps we derive
the Law of Large Numbers for the position of a second class particle under the
initial configuration in which all the positive sites are empty, all the
negative sites are occupied with infinitely many first class particles and with
a single second class particle at the origin. Moreover, we prove that among the
infinite characteristics emanating from the position of the second class
particle, this particle chooses randomly one of them. The randomness is given
in terms of the weak solution of the hydrodynamic equation through some sort of
renormalization function. By coupling the zero-range with the exclusion process
we derive some limiting laws for more general initial conditions.Comment: 22 pages, to appear in Journal of Statistical Physic
Glueball operators and the microscopic approach to N=1 gauge theories
We explain how to generalize Nekrasov's microscopic approach to N=2 gauge
theories to the N=1 case, focusing on the typical example of the U(N) theory
with one adjoint chiral multiplet X and an arbitrary polynomial tree-level
superpotential Tr W(X). We provide a detailed analysis of the generalized
glueball operators and a non-perturbative discussion of the Dijkgraaf-Vafa
matrix model and of the generalized Konishi anomaly equations. We compute in
particular the non-trivial quantum corrections to the Virasoro operators and
algebra that generate these equations. We have performed explicit calculations
up to two instantons, that involve the next-to-leading order corrections in
Nekrasov's Omega-background.Comment: 38 pages, 1 figure and 1 appendix included; v2: typos and the list of
references corrected, version to appear in JHE
The Strehl Ratio in Adaptive Optics Images: Statistics and Estimation
Statistical properties of the intensity in adaptive optics images are usually
modeled with a Rician distribution. We study the central point of the image,
where this model is inappropriate for high to very high correction levels. The
central point is an important problem because it gives the Strehl ratio
distribution. We show that the central point distribution can be modeled using
a non-central Gamma distribution.Comment: 8 pages, 5 figure
Exclusion and zero-range in the rarefaction fan
In these notes we briefly review asymptotic results for the totally asymmetric simple exclusion process and the totally asymmetric constant-rate zero-range process, in the presence of particles with different priorities. We review the Law of Large Numbers for a second class particle added to those systems and we present the proof of crossing probabilities for a second and a third class particles. This is done, for the exclusion process, by means of a particle-hole symmetry argument, while for the zero-range process it is a consequence of a coupling argument.FC
Hadronic interactions of primary cosmic rays with the FLUKA code
The measured fluxes of secondary particles produced by the interactions of
cosmic rays with the astronomical environment represent a powerful tool to
infer some properties of primary cosmic rays. In this work we investigate the
production of secondary particles in inelastic hadronic interactions between
several cosmic rays species of projectiles and different target nuclei of the
interstellar medium. The yields of secondary particles have been calculated
with the FLUKA simulation package, that provides with very good accuracy the
energy distributions of secondary products in a large energy range. An
application to the propagation and production of secondaries in the Galaxy is
presented.Comment: 8 pages, 4 figures; Contribution to the 34th International Cosmic Ray
Conference, July 30 to August 6, The Hague, Netherlands; fixing a typo in the
y-axis label of Fig.
Atmospheric neutrinos in a Large Liquid Argon detector
In view of the evaluation of the physics goals of a large Liquid Argon TPC,
evolving from the ICARUS technology, we have studied the possibility of
performing precision measurements on atmospheric neutrinos. For this purpose we
have improved existing Monte Carlo neutrino event generators based on FLUKA and
NUX by including the 3-flavor oscillation formalism and the numerical treatment
of Earth matter effects. By means of these tools we have studied the
sensitivity in the measurement of Theta(23) through the accurate measurement of
electron neutrinos. The updated values for Delta m^2(23) from Super-Kamiokande
and the mixing parameters as obtained by solar and KamLand experiments have
been used as reference input, while different values of Theta(13) have been
considered. An exposure larger than 500 kton yr seems necessary in order to
achieve a significant result, provided that the present knowledge of systematic
uncertainties is largely improved.Comment: Talk given at the worksgop "Cryogenic Liquid Detectors for Future
Particle Physics", LNGS (Italy) March 13th-14th, 200
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