358,115 research outputs found
Equivalent power law potentials
It is shown that the radial Schroedinger equation for a power law potential
and a particular angular momentum may be transformed using a change of variable
into another Schroedinger equation for a different power law potential and a
different angular momentum. It is shown that this leads to a mapping of the
spectra of the two related power law potentials. It is shown that a similar
correspondence between the classical orbits in the two related power law
potentials exists. The well known correspondence of the Coulomb and oscillator
spectra is a special case of a more general correspondence between power law
potentials.Comment: 10 pages. Typographical mistakes in the earlier version are correcte
Quasi-power law ensembles
Quasi-power law ensembles are discussed from the perspective of nonextensive
Tsallis distributions characterized by a nonextensive parameter . A number
of possible sources of such distributions are presented in more detail. It is
further demonstrated that data suggest that nonextensive parameters deduced
from Tsallis distributions functions , , and from
multiplicity distributions (connected with Tsallis entropy), , are not
identical and that they are connected via . It is also shown
that Tsallis distributions can be obtained directly from Shannon information
entropy, provided some special constraints are imposed. They are connected with
the type of dynamical processes under consideration (additive or
multiplicative). Finally, it is shown how a Tsallis distribution can
accommodate the log-oscillating behavior apparently seen in some multiparticle
data.Comment: 20 pages, 4 figures. Based on the material presented as invited talk
at 27th Marian Smoluchowski Symposium on Statistical Physics, September
22-26, Zakopane, Polan
Anisotropic Power-law Inflation
We study an inflationary scenario in supergravity model with a gauge kinetic
function. We find exact anisotropic power-law inflationary solutions when both
the potential function for an inflaton and the gauge kinetic function are
exponential type. The dynamical system analysis tells us that the anisotropic
power-law inflation is an attractor for a large parameter region.Comment: 14 pages, 1 figure. References added, minor corrections include
Power-law random walks
We present some new results about the distribution of a random walk whose
independent steps follow a Gaussian distribution with exponent
. In the case we show that a stochastic
representation of the point reached after steps of the walk can be
expressed explicitly for all . In the case we show that the random
walk can be interpreted as a projection of an isotropic random walk, i.e. a
random walk with fixed length steps and uniformly distributed directions.Comment: 5 pages, 4 figure
Power-law Parameterized Quintessence Model
We introduce a power-law parameterized quintessence model for the dark energy
which accelerate universe at the low redshifts while behaves as an ordinary
matter for the early universe. We construct a unique scalar potential for this
parameterized quintessence model. As the observational test, the Supernova Type
Ia (SNIa) Gold sample data, size of baryonic acoustic peak from Sloan Digital
Sky Survey (SDSS), the position of the acoustic peak from the CMB observations
and structure formation from the 2dFGRS survey are used to constrain the
parameters of the quintessence model. The best fit parameters indicates that
the equation of state of this model at the present time is less than one
which violates the energy condition in General Relativity. Finally
we compare the age of old objects with age of universe in this model.Comment: 11 pages, 17 figures, submitted to Phys. Rev.
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