The behavior near the singularity of an isotropic, homogeneous cosmological model with a viscous fluid source is investigated. This turns out to be a relaxation dominated regime. Full extended irreversible thermodynamics is used, and comparison with results of the truncated theory is made. New singular behaviors are found and it is shown that a relaxation dominated inflationary epoch may exist ...

If string theory controls physics at the string scale, the dynamics of the early universe before the GUT era will be governed by the low-energy string equations of motion. Studying these equations, we find that depending on the initial conditions when the stringy era starts, and on the time when this era ends, there are a variety of qualitatively distinct types of evolution. Among these is the ...

We present new two-fluid models of accretion disks in active galactic nuclei (AGNs) that aim to address the long-standing problem Toomre instability AGN outskirts. In spirit earlier works by Sirko & Goodman and others, we argue is eventually self-regulated via feedback produced fragmentation its aftermath. Unlike past semianalytic models, which (i) adopt local prescriptions connect star formati...

the sst decomposition method for solving system of linear equations make it possible to obtain the values of roots of the system with the specified accuracy as the limit of the sequence of some vectors. in this topic we are going to consider vectors as fuzzy vectors. we have considered a numerical example and tried to find out solution vector x in fuzzified form using method of sst decomposition.