1,442 research outputs found
On the Gauss map of embedded minimal tubes
A surface is called a tube if its level-sets with respect to some coordinate
function (the axis of the surface) are compact. Any tube of zero mean curvature
has an invariant, the so-called flow vector. We study how the geometry of the
Gaussian image of a higher-dimensional minimal tube M is controlled by the
angle alpha(M) between the axis and the flow vector of M. We prove that the
diameter of the Gauss image of M is at least 2alpha(M). As a consequence we
derive an estimate on the length of a two-dimensional minimal tube M in terms
of alpha(\M) and the total Gaussian curvature of M
Production of Massive Fermions at Preheating and Leptogenesis
We present a complete computation of the inflaton decay into very massive
fermions during preheating. We show that heavy fermions are produced very
efficiently up to masses of order 10^{17}-10^{18} GeV; the accessible mass
range is thus even broader than the one for heavy bosons. We apply our findings
to the leptogenesis scenario, proposing a new version of it, in which the
massive right-handed neutrinos, responsible for the generation of the baryon
asymmetry, are produced during preheating. We also discuss other production
mechanisms of right-handed neutrinos in the early Universe, identifying the
neutrino mass parameters for which the observed baryon asymmetry is reproduced.Comment: 29 pages, 4 figure
Features of translating technical terms in Portuguese and English
The article deals with the main difficulties and features of militar
Denjoy-Ahlfors Theorem for Harmonic Functions on Riemannian Manifolds and External Structure of Minimal Surfaces
We extend the well-known Denjoy-Ahlfors theorem on the number of different
asymptotic tracts of holomorphic functions to subharmonic functions on
arbitrary Riemannian manifolds. We obtain some new versions of the Liouville
theorem for \p-harmonic functions without requiring the geodesic completeness
requirement of a manifold. Moreover, an upper estimate of the topological index
of the height function on a minimal surface in has been established
and, as a consequence, a new proof of Bernstein's theorem on entire solutions
has been derived. Other applications to minimal surfaces are also discussed.Comment: 30 page
Quantum Dew
We consider phase separation in nonequilibrium Bose gas with an attractive
interaction between the particles. Using numerical integrations on a lattice,
we show that the system evolves into a state that contains drops of
Bose-Einstein condensate suspended in uncondensed gas. When the initial gas is
sufficiently rarefied, the rate of formation of this quantum dew scales with
the initial density as expected for a process governed by two-particle
collisions.Comment: 4 pages, revtex, 5 figure
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