2,116,622 research outputs found
A connected F-space
We present an example of a compact connected F-space with a continuous
real-valued function f for which the union of the interiors of its fibers is
not dense. This indirectly answers a question from Abramovich and Kitover in
the negative
Perdurance of multiply connected de Sitter space
This paper deals with a study of the effects that spherically symmetric
first-order metric perturbations and vacuum quantum fluctuations have on the
stability of the multiply connected de Sitter spacetime recently proposed by
Gott and Li. It is the main conclusion of this study that although such a
spacetime is stable to the classical metric perturbations for any size of the
nonchronal region, it is only stable against the quantum fluctuations of vacuum
if the size of the multiply connected region is of the order the Planck scale.
Therefore, boundary conditions for the state of the universe based on the
notion that the universe created itself in a regime where closed timelike
curves were operative and stable, still appear to be physically and
philosophically so well supported as are those boundary conditions relying on
the notion that the universe was created out of nothing.Comment: 13 pages, RevTe
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