16,025 research outputs found
Aspects of production and kinetic decoupling of non-thermal dark matter
We reconsider non-thermal production of WIMP dark matter in a systematic way
and using a numerical code for accurate computations of dark matter relic
densities. Candidates with large pair annihilation rates are favored,
suggesting a connection with the anomalies in the lepton cosmic-ray flux
detected by Pamela and Fermi. Focussing on supersymmetric models we will
consider the impact of non-thermal production on the preferred mass scale for
dark matter neutralinos. We have also developed a new formalism to solve the
Boltzmann's equation for a system of coannihilating species without assuming
kinetic equilibrium and applied it to the case of pure Winos.Comment: Proceedings for the conference TAUP 201
Superconductors from Superstrings
We establish that in a large class of strongly coupled 3+1 dimensional N=1
quiver conformal field theories with gravity duals, adding a chemical potential
for the R-charge leads to the existence of superfluid states in which a chiral
primary operator of the schematic form O = \lambda\lambda + W condenses. Here
\lambda is a gluino and W is the superpotential. Our argument is based on the
construction of a consistent truncation of type IIB supergravity that includes
a U(1) gauge field and a complex scalar.Comment: 5 pages, 2 figures; v2 improved figure, small change
Phase Transition and Hybrid Star in a Nonlinear model
The phase transition between the nuclear matter and the quark matter is
examined. The relativistic mean field theory(RMF) is consider with interacting
nucleons and mesons using TM1 parameter set for the nuclear matter equations of
state. It is found that the trasition point depends on coupling constant
and bag pressure. From the study of the structure of a hybrid
neutron star, it is observed that the star contains quark matter in the
interior and neutron matter on the outer perifery.Comment: 8 pages, 7 figures, to appear in Int. J. Mod. Phy.
Type IIA Orientifold Limit of M-Theory on Compact Joyce 8-Manifold of Spin(7)-Holonomy
We show that M-theory compactified on a compact Joyce 8-manifold of
-holonomy, which yields an effective theory in with = 1
supersymmetry, admits at some special points in it moduli space a description
in terms of type IIA theory on an orientifold of compact Joyce 7-manifold of
-holonomy. We find the evidence in favour of this duality by computing the
massless spectra on both M-thory side and type IIA side. For the latter, we
compute the massless spectra by going to the orbifold limit of the Joyce
7-manifold.Comment: 26 pages, 2 eps figures, Latex file, two references and one footnote
added, corrected some typo
Superconformal field theories from crystal lattices
We propose a brane configuration for the (2+1)d,
superconformal theories (CFT) arising from M2-branes probing toric
Calabi-Yau 4-fold cones, using a T-duality transformation of M-theory. We
obtain intersections of M5-branes on a three-torus which form a 3d bipartite
crystal lattice in a way similar to the 2d dimer models for CFT. The
fundamental fields of the CFT are M2-brane discs localized around the
intersections, and the super-potential terms are identified with the atoms of
the crystal. The model correctly reproduces the complete BPS spectrum of mesons
and baryons.Comment: 4 pages, 4 figures, revtex; v2. references added, minor correction
Hepatitis B, C and D viral markers in multitransfused thalassemic children: long term complications and present management
This article does not have an abstract
Distance Product of Graphs
In graph theory, different types of product of two graphs have been studied, e.g. Cartesian product, Tensor product, Strong product, etc. Later on, Cartesian product and Tensor product have been generalized by 2-Cartesian product and 2-Tensor product. In this paper, we give one more generalize form, distance product of two graphs. Mainly we discuss the connectedness, bipartiteness and Eulerian property in this product
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