45,222 research outputs found
SUSY Dark Matter In Light Of CDMS/XENON Limits
In this talk we briefly review the current CDMS/XENON constraints on the
neutralino dark matter in three popular supersymmetric models: the minimal
(MSSM), the next-to-minimal (NMSSM) and the nearly minimal (nMSSM). The
constraints from the dark matter relic density and various collider experiments
are also taken into account. The conclusion is that for each model the current
CDMS/XENON limits can readily exclude a large part of the parameter space
allowed by other constraints and the future SuperCDMS or XENON100 can cover
most of the allowed parameter space. The implication for the Higgs search at
the LHC is also discussed. It is found that in the currently allowed parameter
space the MSSM charged Higgs boson is quite unlikely to be discovered at the
LHC while the neutral Higgs bosons and may be accessible at the LHC in
the parameter space with a large parameter.Comment: talk given at 2nd International Workshop on Dark Matter, Dark Energy
and Matter-Antimatter Asymmetry, Nov 5-6, 2010, Hsinchu, Taiwan (to appear in
Int. J. Mod. Phys. D
Closed-loop control strategy with improved current for a flashing ratchet
We show how to switch on and off the ratchet potential of a collective
Brownian motor, depending only on the position of the particles, in order to
attain a current higher than or at least equal to that induced by any periodic
flashing. Maximization of instant velocity turns out to be the optimal protocol
for one particle but is nevertheless defeated by a periodic switching when a
sufficiently large ensemble of particles is considered. The protocol presented
in this article, although not the optimal one, yields approximately the same
current as the optimal protocol for one particle and as the optimal periodic
switching for an infinite number of them.Comment: 4 pages, 4 figure
Wijsman Hyperspaces: Subspaces and Embeddings
In this paper, topological properties of Wijsman hyperspaces are
investigated. We study the existence of isolated points in Wijsman hyperspaces.
We show that every Tychonoff space can be embedded as a closed subspace in the
Wijsman hyperspace of a complete metric space which is locally R.Comment: 6 page
Hierarchical growing neural gas
“The original publication is available at www.springerlink.com”. Copyright Springer.This paper describes TreeGNG, a top-down unsupervised learning method that produces hierarchical classification schemes. TreeGNG is an extension to the Growing Neural Gas algorithm that maintains a time history of the learned topological mapping. TreeGNG is able to correct poor decisions made during the early phases of the construction of the tree, and provides the novel ability to influence the general shape and form of the learned hierarchy
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