4,831 research outputs found
Limiting distributions of continuous-time random walks with superheavy-tailed waiting times
We study the long-time behavior of the scaled walker (particle) position
associated with decoupled continuous-time random walk which is characterized by
superheavy-tailed distribution of waiting times and asymmetric heavy-tailed
distribution of jump lengths. Both the scaling function and the corresponding
limiting probability density are determined for all admissible values of tail
indexes describing the jump distribution. To analytically investigate the
limiting density function, we derive a number of different representations of
this function and, by this way, establish its main properties. We also develop
an efficient numerical method for computing the limiting probability density
and compare our analytical and numerical results.Comment: 35 pages, 4 figure
Probing the deuteron structure at small NN distances by antiproton-deuteron annihilation
The production of pions by antiproton-deuteron annihilation at rest is
analyzed. Assuming the possible existence of two delta-isobars in a deuteron
some enhancement in the distribution over the invariant mass of two negative
charged pions is predicted.Comment: 12 pages, Latex and Postscrip
Magnetic relaxation in finite two-dimensional nanoparticle ensembles
We study the slow phase of thermally activated magnetic relaxation in finite
two-dimensional ensembles of dipolar interacting ferromagnetic nanoparticles
whose easy axes of magnetization are perpendicular to the distribution plane.
We develop a method to numerically simulate the magnetic relaxation for the
case that the smallest heights of the potential barriers between the
equilibrium directions of the nanoparticle magnetic moments are much larger
than the thermal energy. Within this framework, we analyze in detail the role
that the correlations of the nanoparticle magnetic moments and the finite size
of the nanoparticle ensemble play in magnetic relaxation.Comment: 21 pages, 4 figure
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