2 research outputs found
Accretion of Chaplygin gas upon black holes: Formation of faster outflowing winds
We study the accretion of modified Chaplygin gas upon different types of
black hole. Modified Chaplygin gas is one of the best candidates for a combined
model of dark matter and dark energy. In addition, from a field theoretical
point of view the modified Chaplygin gas model is equivalent to that of a
scalar field having a self-interacting potential. We formulate the equations
related to both spherical accretion and disc accretion, and respective winds.
The corresponding numerical solutions of the flow, particularly of velocity,
are presented and are analyzed. We show that the accretion-wind system of
modified Chaplygin gas dramatically alters the wind solutions, producing faster
winds, upon changes in physical parameters, while accretion solutions
qualitatively remain unaffected. This implies that modified Chaplygin gas is
more prone to produce outflow which is the natural consequence of the dark
energy into the system.Comment: 21 pages including 7 figures; published in Classical and Quantum
Gravit
How does Inflation Depend Upon the Nature of Fluids Filling Up the Universe in Brane World Scenario
By constructing different parameters which are able to give us the
information about our universe during inflation,(specially at the start and the
end of the inflationary universe) a brief idea of brane world inflation is
given in this work. What will be the size of the universe at the end of
inflation,i.e.,how many times will it grow than today's size is been speculated
and analysed thereafter. Different kinds of fluids are taken to be the matter
inside the brane. It is observed that in the case of highly positive pressure
grower gas like polytropic,the size of the universe at the end of inflation is
comparitively smaller. Whereas for negative pressure creators (like chaplygin
gas) this size is much bigger. Except thse two cases, inflation has been
studied for barotropic fluid and linear redshift parametrization too. For them the size of the universe after
inflation is much more high. We also have seen that this size does not depend
upon the potential energy at the end of the inflation. On the contrary, there
is a high impact of the initial potential energy upon the size of inflation.Comment: 20 page