14,591 research outputs found
Spectral Characters of Finite-Dimensional Representations of Affine Algebras
We introduce the notion of a spectral character for finite-dimensional
representations of affine algebras. These can be viewed as a suitable q=1 limit
of the elliptic characters defined by Etingof and Moura for quantum affine
algebras. We show that these characters determine blocks of the category of
finite-dimensional modules for affine algebras. To do this we use the Weyl
modules defined by Chari and Pressley and some indecomposable reducible
quotient of the Weyl modules.Comment: More concise proofs for Propositions 1.2 and 2.4 added. To appear in
Journal of Algebr
Scalable Detection and Isolation of Phishing
This paper presents a proposal for scalable detection and isolation of phishing. The main ideas are to move the protection from end users towards the network provider and to employ the novel bad neighborhood concept, in order to detect and isolate both phishing e-mail senders and phishing web servers. In addition, we propose to develop a self-management architecture that enables ISPs to protect their users against phishing attacks, and explain how this architecture could be evaluated. This proposal is the result of half a year of research work at the University of Twente (UT), and it is aimed at a Ph.D. thesis in 2012
New Analyses of Double-Bang Events in the Atmosphere
We use CORSIKA+Herwig simulation code to produce ultra-high energy neutrino
interactions in the atmosphere. Our aim is to reproduce extensive air showers
originated by extragalactic tau-neutrinos. For charged current tau-neutrino
interactions in the atmosphere, beside the air shower originated from the
neutrino interaction, it is expected that a tau is created and may decay before
reaching the ground. That phenomenon makes possible the generation of two
related extensive air showers, the so called Double-Bang event. We make an
analysis of the main characteristics of Double-Bang events in the atmosphere
for mean values of the parameters involved in such phenomenon, like the
inelasticity and tau decay length. We discuss what may happen for the ``out of
the average'' cases and conclude that it may be possible to observe this kind
of event in ultra-high energy cosmic ray observatories such as Pierre Auger or
Telescope Array.Comment: 17 pages, 5 figures, final version to appear in BJ
Scalar Dark Matter in light of LEP and ILC Experiments
In this work we study a scalar field dark matter model with mass of the order
of 100 MeV. We assume dark matter is produced in the process , that, in fact, could be a background for the standard process
extensively studied at LEP. We constrain the
chiral couplings, and , of the dark matter with electrons through an
intermediate fermion of mass GeV and obtain and
for the best fit point of our analysis. We also
analyze the potential of ILC to detect this scalar dark matter for two
configurations: (i) center of mass energy GeV and luminosity
fb, and (ii) center of mass energy TeV
and luminosity fb. The differences of polarized beams
are also explored to better study the chiral couplings.Comment: 15 pages, 6 figures and 1 table. New references added and
improvements in the text. Conclusions unchange
Spatio-temporal conjecture for diffusion
We present here a conjecture about the equivalence between the noise density
of states of a system governed by a generalized Langevin equation and the
fluctuation in the energy density of states in a Hamiltonian system. We present
evidence of this for a disordered Heisenberg system.Comment: 6 pages, 1 figure. Submitted to Physica
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