28,329 research outputs found
On an approach to constructing static ball models in General Relativity
An approach to construction of static models is demonstrated for a fluid
ball. Five examples are considered. Two of them are exact solutions of the
Einstein equations; the other three are connected with the Airy special
functions, the hypergeometric functions and the Heun functions.Comment: 3 pages, Talk given at the International Conference RUSGRAV-14, June
27--July 4, 2011, Ulyanovsk, Russi
Combined Analysis of Two- and Three-Particle Correlations in q,p-Bose Gas Model
q-deformed oscillators and the q-Bose gas model enable effective description
of the observed non-Bose type behavior of the intercept ("strength")
of two-particle correlation function
of identical pions produced in heavy-ion collisions. Three-
and n-particle correlation functions of pions (or kaons) encode more
information on the nature of the emitting sources in such experiments. And so,
the q-Bose gas model was further developed: the intercepts of n-th order
correlators of q-bosons and the n-particle correlation intercepts within the
q,p-Bose gas model have been obtained, the result useful for quantum optics,
too. Here we present the combined analysis of two- and three-pion correlation
intercepts for the q-Bose gas model and its q,p-extension, and confront with
empirical data (from CERN SPS and STAR/RHIC) on pion correlations. Similar to
explicit dependence of on mean momenta of particles (pions,
kaons) found earlier, here we explore the peculiar behavior, versus mean
momentum, of the 3-particle correlation intercept . The whole
approach implies complete chaoticity of sources, unlike other joint
descriptions of two- and three-pion correlations using two phenomenological
parameters (e.g., core-halo fraction plus partial coherence of sources).Comment: Published in SIGMA (Symmetry, Integrability and Geometry: Methods and
Applications) at http://www.emis.de/journals/SIGMA
Complete determination of the orbital parameters of a system with N+1 bodies using a simple Fourier analysis of the data
Here we show how to determine the orbital parameters of a system composed of
a star and N companions (that can be planets, brown-dwarfs or other stars),
using a simple Fourier analysis of the radial velocity data of the star. This
method supposes that all objects in the system follow keplerian orbits around
the star and gives better results for a large number of observational points.
The orbital parameters may present some errors, but they are an excellent
starting point for the traditional minimization methods such as the
Levenberg-Marquardt algorithms.Comment: 4 page
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