Intrinsic energy of Lemaître-Tolman-Bondi models and cosmological implications

Recently, some Lemaître-Tolman-Bondi metrics have been considered as models alternative to the dark energy within the Friedmann-Lemaître-Robertson-Walker universes. The vanishing of the intrinsic energy of these metrics is examined since such a vanishing, in the present case and in general, could be interpreted as a necessary condition to consider the possibility of the quantum creation of a metric. More specifically, this vanishing is examined in the particular case where the Lemaître-Tolman-Bondi metrics behave asymptotically like a Friedmann-Lemaître-Robertson-Walker universe. Finally, we deal with a particular model ruled out after being confronted with cosmic observations. In a minimal agreement with this negative result, leaving aside an unstable case, the value of the intrinsic energy of this particular model does not vanish and becomes in fact minus infinite

Cosmic censorship conjecture in some matching spherical collapsing metrics

A physically plausible Lemaître-Tolman-Bondi collapse in the marginally bound case is considered. By 'physically plausible,' we mean that the corresponding metric is C1 matched at the collapsing star surface and further that its intrinsic energy is, as due, stationary and finite. It is proved for this Lemaître-Tolman-Bondi collapse, for some parameter values, that its intrinsic central singularity is globally naked, thus violating the cosmic censorship conjecture with, for each direction, one photon, or perhaps a pencil of photons, leaving the singularity and reaching the null infinity. Our result is discussed in relation to some other cases in the current literature on the subject in which some of the central singularities are globally naked, too

Inflation for Bianchi IX model

The influence of Inflation on initial (i.e. at Planck's epoch) large anisotropy of the Universe is studied, considering a more general metric than the isotropic one: the locally rotationally symmetric (L.R.S.) Bianchi IX metric. We find, then, a large set of initial conditions of intrinsic curvature and shear allowing an inflationary epoch that make the anisotropy negligible. These are not trivial because of the non-linearity of the Einstein's equations.Comment: 10 pages, Latex. To be published in Phisical Review