5,892 research outputs found
Casimir Effect in the Rainbow Einstein's Universe
In the present paper we investigate the effects caused by the modification of
the dispersion relation obtained by solving the Klein-Gordon equation in the
closed Einstein's universe in the context of rainbow's gravity models. Thus, we
analyse how the quantum vacuum fluctuations of the scalar field are modified
when compared with the results obtained in the usual General Relativity
scenario. The regularization, and consequently the renormalization, of the
vacuum energy is performed adopting the Epstein-Hurwitz and Riemann's zeta
functions.Comment: 15 pages, 1 figure. To appear in Europhysics Letter
A Note on the Robustness of Pair Separations Methods in Cosmic Topology
The pair separations statistical methods devised to detect the topology of
the universe rely on the accurate knowledge of the three-dimensional positions
of the cosmic sources. The determination of these positions, however, involves
inevitable observational uncertainties. The only significant (measurable) sign
of a nontrivial topology in PSH's was shown to be spikes. We briefly report our
results concerning the sensitivity of the topological spikes in the presence of
the uncertainties in the positions of the cosmic sources, which arise from
uncertainties in the values of the density parameters.Comment: To appear in the Proc. of 10th Marcel Grossmann Meeting on General
Relativity. Latex2e, World Scientific proc. style files, 2 figs., 4 page
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