ﻻ يوجد ملخص باللغة العربية
Friedmann-Robertson-Walker cosmological models with a massive scalar field are studied in the presence of hydrodynamical matter in the form of a perfect fluid. The ratio of the number of solutions without inflation to the total number of solutions is evaluated, depending on the fluid density. It is shown that in a closed model this ratio can reach 60%, by contrast to $sim 30 %$ in models without fluid.
The chaotic behavior in FRW cosmology with a scalar field is studied for scalar field potentials less steep than quadratic. We describe a transition to much stronger chaos for appropriate parameters of such potentials. The range of parameters which a
The results on chaos in FRW cosmology with a massive scalar field are extended to another scalar field potential. It is shown that for sufficiently steep potentials the chaos disappears. A simple and rather accurate analytical criterion for the chaos
We shall discuss the general relativistic generation of spikes in a massless scalar field or stiff perfect fluid model. We first investigate orthogonally transitive (OT) $G_2$ stiff fluid spike models both heuristically and numerically, and give a ne
Assuming that a scalar field controls the inflationary era, we examine the combined effects of string and $f(R)$ gravity corrections on the inflationary dynamics of canonical scalar field inflation, imposing the constraint that the speed of the primo
Using the Ponce de Leon background metric, which describes a 5D universe in an apparent vacuum: $bar{G}_{AB}=0$, we study the effective 4D evolution of both, the inflaton and gauge-invariant scalar metric fluctuations, in the recently introduced model of space time matter inflation.