463 research outputs found
Some Unique Constants Associated with Extremal Black Holes
In recent papers we had developed a unified picture of black hole entropy and
curvature which was shown to lead to Hawking radiation. It was shown that for
any black hole mass, holography implies a phase space of just one quantum
associated with the interior of the black hole. Here we study extremal rotating
and charged black holes and obtain unique values for ratios of angular momentum
to entropy, charge to entropy, etc. It turns out that these ratios can be
expressed in terms of fundamental constants in nature, having analogies with
other physical systems, like in condensed matter physics.Comment: "Accepted for publication in Astrophysics & Space Science" 4 pages,
10 equation
Dieterici gas as a Unified Model for Dark Matter and Dark Energy
The dominance of dark energy in the universe has necessitated the
introduction of a repulsive gravity source to make q0 negative. The models for
dark energy range from a simple lambda-term to quintessence, Chaplygin gas,
etc. We look at the possibility of how change of behaviour of missing energy
density, from DM to DE, may be determined by the change in the equation of
state of a background fluid instead of a form of potential. The question of
cosmic acceleration can be discussed within the framework of theories which do
not necessarily include scalar fields.Comment: 9 pages, 38 equation
A Brief History of Dark Energy
Gurzadyan-Xue Dark Energy was derived in 1986 (twenty years before the paper
of Gurzadyan-Xue). The paper by the present author, titled The Planck Length as
a Cosmological Constant, published in Astrophysics Space Science, Vol. 127,
p.133-137, 1986 contains the formula claimed to have been derived by
Gurzadyan-Xue (in 2003)
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