13,148 research outputs found
Some notes on the Big Trip
The big trip is a cosmological process thought to occur in the future by
which the entire universe would be engulfed inside a gigantic wormhole and
might travel through it along space and time. In this paper we discuss
different arguments that have been raised against the viability of that
process, reaching the conclusions that the process can actually occur by
accretion of phantom energy onto the wormholes and that it is stable and might
occur in the global context of a multiverse model. We finally argue that the
big trip does not contradict any holographic bounds on entropy and information.Comment: 8 pages, no figures, LaTe
Toric embedded resolutions of quasi-ordinary hypersurface singularities
We build two embedded resolution procedures of a quasi-ordinary singularity
of complex analytic hypersurface, by using toric morphisms which depend only on
the characteristic monomials associated to a quasi-ordinary projection of the
singularity. This result answers an open problem of Lipman in Equisingularity
and simultaneous resolution of singularities, Resolution of Singularities,
Progress in Mathematics No. 181, 2000, 485-503. In the first procedure the
singularity is embedded as hypersurface. In the second procedure, which is
inspired by a work of Goldin and Teissier for plane curves (see Resolving
singularities of plane analytic branches with one toric morphism,loc. cit.,
pages 315-340), we re-embed the singularity in an affine space of bigger
dimension in such a way that one toric morphism provides its embedded
resolution. We compare both procedures and we show that they coincide under
suitable hypothesis.Comment: To apear in Annales de l'Institut Fourier (Grenoble
Dark energy without dark energy
It is proposed that the current acceleration of the universe is not
originated by the existence of a mysterious dark energy fluid nor by the action
of extra terms in the gravity Lagrangian, but just from the sub-quantum
potential associated with the CMB particles. The resulting cosmic scenario
corresponds to a benigner phantom model which is free from the main problems of
the current phantom approaches.Comment: 4 pages, 1 figure, to appear in AIP proceedings of "Dark side of the
Universe
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