The interaction energy between two black holes at large separation distance is calculated. The first term in the expansion corresponds to the Newtonian interaction between the masses. The second term corresponds to the spin-spin interaction. The calculation is based on the interaction energy defined on the two black holes initial data. No test particle approximation is used. The relation betwee...

We investigate the dynamics of an homogenous distribution of galaxies moving under the cosmological expansion through Euler-Poisson equations system. The solutions are interpreted with the aim of understanding the cosmic velocity fields in the Local Super Cluster, and in particular the presence of a bulk flow. Among several solutions, we shows a planar kinematics with constant (eternal) and rot...

In this letter we study a model of interaction between the scalar field and an inhomogeneous ideal fluid. We have considered two forms of the ideal fluid and a power law expansion for the scale factor. We have solved the equations for the energy densities. Also we show that besides being a dark energy model to explain the cosmic acceleration, this model shows a decaying nature of the scalar fie...

An epoch of accelerated expansion, or inflation, in the early universe solves several cosmological problems. While there are many models of inflation only recently has it become possible to discriminate between some of the models using observations of the cosmic microwave background radiation and large-scale structure. In this talk, we discuss inflation and its observational consequences, and t...

The Cosmic Defect (CD) theory is reviewed and used to fit the data for the accelerated expansion of the universe, obtained from the apparent luminosity of 192 SnIa’s. The fit from CD is compared with the one obtained by means of ΛCDM. The results from both theories are in good agreement and the fits are satisfactory. The correspondence between both approaches is discussed and interpreted.

Quintessence, a time-varying energy component that may account for the accelerated expansion of the universe, can be characterized by its equation of state and sound speed. In this paper, we show that if the quintessence density is at least 1% of the critical density at the surface of last scattering the cosmic microwave background anisotropy can distinguish between models whose sound speed is ...

We investigate the big-bang nucleosynthesis in a Brans-Dicke model with a varying Λ term using the Monte-Carlo method and likelihood analysis. It is found that the cosmic expansion rate differs appreciably from that of the standard model. The produced abundances of He, D, and barely Li are consistent with the observed ones within the uncertainties in nuclear reaction rates when the baryon to ph...

A fast (∼ 3 ms) adiabatic expansion of a volume of liquid He through the lambda transition is being used to study the nature of the transition and to model the cosmological false vacuum to true vacuum phase transition of the early universe. Preliminary results are reported showing that, in accordance with theoretical predictions by W H Zurek (Nature 317, 505; 1985), there is copious production ...

The local expansion field (v220 < 1200 kms ) and the cosmic expansion field out to 30 000 kms are characterized by H0 = 58 [km s −1 Mpc]. While the random error of this determination is small (±2 units), it may still be affected by systematic errors as large as ±10%. The local expansion is outlined by Cepheids and by Cepheid-calibrated TF distances of a complete sample of field galaxies and by ...

by Xinghai Zhao In this dissertation, we explore two outstanding questions in the formation and evolution of the large-scale structure. One question is that general relativistic corrections to the expansion rate of the universe arise when the Einstein equations are averaged over a spatial volume in a locally inhomogeneous cosmology. It has been suggested that they may contribute to the observed...