13,328 research outputs found
Recovery of normal heat conduction in harmonic chains with correlated disorder
We consider heat transport in one-dimensional harmonic chains with isotopic
disorder, focussing our attention mainly on how disorder correlations affect
heat conduction. Our approach reveals that long-range correlations can change
the number of low-frequency extended states. As a result, with a proper choice
of correlations one can control how the conductivity scales with the
chain length . We present a detailed analysis of the role of specific
long-range correlations for which a size-independent conductivity is exactly
recovered in the case of fixed boundary conditions. As for free boundary
conditions, we show that disorder correlations can lead to a conductivity
scaling as , with the scaling exponent
being arbitrarily small (although not strictly zero), so that
normal conduction is almost recovered even in this case.Comment: 15 pages, 2 figure
Dynamics of Viscous Dissipative Plane Symmetric Gravitational Collapse
We present dynamical description of gravitational collapse in view of Misner
and Sharp's formalism. Matter under consideration is a complicated fluid
consistent with plane symmetry which we assume to undergo dissipation in the
form of heat flow, radiation, shear and bulk viscosity. Junction conditions are
studied for a general spacetime in the interior and Vaidya spacetime in the
exterior regions. Dynamical equations are obtained and coupled with causal
transport equations derived in context of Mller Israel Stewart
theory. The role of dissipative quantities over collapse is investigated.Comment: 17 pages, accepted for publication in Gen. Relativ. Gra
Dalitz plot slope parameters for decays and two particle interference
We study the possible distortion of phase-space in the decays , which may result from final state interference among the decay products.
Such distortion may influence the values of slope parameters extracted from the
Dalitz plot distribution of these decays. We comment on the consequences on the
magnitude of violation of the rule in these decays.Comment: 17 pages, LaTex2e, 6 figures, v2 authors' affiliation modified, to
appear in Mod. Phys. Lett.
Conformal Dynamics of Precursors to Fracture
An exact integro-differential equation for the conformal map from the unit
circle to the boundary of an evolving cavity in a stressed 2-dimensional solid
is derived. This equation provides an accurate description of the dynamics of
precursors to fracture when surface diffusion is important. The solution
predicts the creation of sharp grooves that eventually lead to material failure
via rapid fracture. Solutions of the new equation are demonstrated for the
dynamics of an elliptical cavity and the stability of a circular cavity under
biaxial stress, including the effects of surface stress.Comment: 4 pages, 3 figure
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