4,930 research outputs found
Polynomial and rational solutions of holonomic systems
The aim of this paper is to give two new algorithms, which are elimination
free, to find polynomial and rational solutions for a given holonomic system
associated to a set of linear differential operators in the Weyl algebra D =
k where k is a subfield of the complex numbers.Comment: 20 page
Goldilocks Supersymmetry: Simultaneous Solution to the Dark Matter and Flavor Problems of Supersymmetry
Neutralino dark matter is well motivated, but also suffers from two
shortcomings: it requires gravity-mediated supersymmetry breaking, which
generically violates flavor constraints, and its thermal relic density \Omega
is typically too large. We propose a simple solution to both problems:
neutralinos freezeout with \Omega ~10-100, but then decay to ~1 GeV gravitinos,
which are simultaneously light enough to satisfy flavor constraints and heavy
enough to be all of dark matter. This scenario is naturally realized in
high-scale gauge-mediation models, ameliorates small scale structure problems,
and implies that ``cosmologically excluded'' models may, in fact, be
cosmologically preferred.Comment: 4 pages; v2: references added; v3: published versio
Atomic Bose-Fermi mixed condensates with Boson-Fermion quasi-bound cluster states
The boson-fermion atomic bound states (composite fermion) and their roles for
the phase structures are studied in a bose-fermi mixed condensate of atomic gas
in finite temperature and density. The two-body scattering equation is
formulated for a boson-fermion pair in the mixed condensate with the
Yamaguchi-type potential. By solving the equation, we evaluate the binding
energy of a composite fermion, and show that it has small T-dependence in the
physical region, because of the cancellation of the boson- and fermion-
statistical factors in the equation. We also calculate the phase structure of
the BF mixed condensate under the equilibrium B+F -> BF, and discuss the role
of the composite fermions: the competitions between the degenerate state of the
composite fermions and the Bose-Einstein condensate (BEC) of isolated bosons.
The criterion for the BEC realization is obtained from the
algebraically-derived phase diagrams at T=0.Comment: 5 pages, 3 figure
Numerical Simulation of Permanent Magnet Method for Measuring Critical Current Density in Superconducting Film: Dominant Experimental Conditions for Crack Detection
AbstractThe scanning permanent magnet method for measuring the critical current density in a high-temperature superconduct- ing (HTS) film has been reproduced numerically. For this purpose, a numerical code has been developed for analyzing the time evolution of a shielding current density in an HTS film with a crack. The results of computations show that the attractive force Fr and repulsive one Fa are observed near the endpoints of the crack when the symmetry axis of the magnet approaches the crack. In addition, the both forces, Fr and Fa, have the maximum value only when the magnet is located above the crack. This means that the crack size and position can be estimated by using the scanning method
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