322 research outputs found
Analysis of inflationary cosmological models in gauge theories of gravitation
Inflationary homogeneous isotropic cosmological models filled by scalar
fields and ultrarelativistic matter are examined in the framework of gauge
theories of gravitation. By using quadratic scalar field potential numerical
analysis of flat, open and closed models is curried out. Properties of
cosmological models are investigated in dependence on indefinite parameter of
cosmological equations and initial conditions at a bounce. Fulfilled analysis
demonstrates regular character of all cosmological models.Comment: LaTeX2e, iopart class file, 12 pages, 19 figure
Improved success rate and stability for phase retrieval by including randomized overrelaxation in the hybrid input output algorithm
In this paper, we study the success rate of the reconstruction of objects of
finite extent given the magnitude of its Fourier transform and its geometrical
shape. We demonstrate that the commonly used combination of the hybrid input
output and error reduction algorithm is significantly outperformed by an
extension of this algorithm based on randomized overrelaxation. In most cases,
this extension tremendously enhances the success rate of reconstructions for a
fixed number of iterations as compared to reconstructions solely based on the
traditional algorithm. The good scaling properties in terms of computational
time and memory requirements of the original algorithm are not influenced by
this extension.Comment: 14 pages, 8 figure
Non-Singular Cosmology and Gauge Theories of Gravitation
The resolution of the problem of cosmological singularity in the framework of
gauge theories of gravitation is discussed. Generalized cosmological Friedmann
equations for homogeneous isotropic models filled by interacting scalar fields
and usual gravitating matter are deduced. It is shown that generic feature of
cosmological models of flat, open and closed type is their regular bouncing
character.Comment: LaTeX2e, 16 page
- …