In this talk, we touch upon the chaotic and fractal aspects of the Universe.

Although quintessence cosmologies seem to explain the amount of cosmological constant today, the required conditions are severe. For example, an extremely slowly varying and light scalar field that rolls toward the vanishing vacuum energy state is needed, which must satisfy the required initial conditions so that the energy density in matter is comparable to the energy density stored in quintes...

Pseudo-supersymmetric solutions of minimal N = 2, D = 4 de Sitter supergravity are classified using spinorial geometry techniques. We find two classes of solutions, the first is the cosmological Majumdar-Papapetrou solution of Kastor and Traschen, and the second corresponds to gravitational waves propagating in the Nariai cosmology.

In general relativity, there is a well-developed formalism for working with the approximation that a gravitational source is concentrated on a shell, or codimension one surface. By contrast, there are obstacles to concentrating sources on surfaces that have a higher co-dimension, for example, a string in a spacetime with dimension greater than or equal to four. Here it is shown that, by giving ...

A new Einstein–Hilbert type action of superon-graviton model (SGM) for space-time and matter is obtained based upon the geometrical arguments of the higher symmetric (SGM) space-time. SGM action is invariant under [global NL SUSY] ⊗ [local GL(4,R)] ⊗ [local Lorentz]⊗ [global SO(N)]. The explicit form of SGM action is given in terms of the fields of the graviton and superons by using the affine ...

The internal structure of the Newton star with the uniform density is considered within the framework of the fractal universe with a power index of 2. The temperature profile in the star follows the law of 4/3. With the use of this profile, the neutrino flux from the sun is estimated. The obtained value of the neutrino flux may provide a solution for the solar neutrino puzzle. The analysis of g...

We reanalyse the sphaleron bound of electroweak baryogenesis when allowing deviations to the Friedmann equation. These modifications are well motivated in the context of brane cosmology where they appear generically without being in conflict with major experimental constraints on four-dimensional gravity. While suppressed at the time of nucleosynthesis, these corrections can dominate at the tim...