No realistic wormholes from ghostfree scalartensor phantom dark energy
Abstract
It is proven that no wormholes can be formed in viable scalartensor models of dark energy admitting its phantomlike ( w < 1) behavior in cosmology, even in the presence of electric or magnetic fields, if the nonminimal coupling function f(Φ) is positive everywhere and the scalar field Φ itself is not a ghost. Some special static, spherically symmetric wormhole solutions may exist if f(Φ) is allowed to reach zero or to become negative, so that the effective gravitational constant becomes negative in some region making the graviton a ghost. If f remains nonnegative, such solutions require severe finetuning and a very peculiar kind of model. If f < 0 is allowed, it is argued (and confirmed by previous investigations) that such solutions are generically unstable under nonstatic perturbations, the instability appearing right near transition surfaces to negative f.
 Publication:

Soviet Journal of Experimental and Theoretical Physics Letters
 Pub Date:
 March 2007
 DOI:
 10.1134/S0021364007010018
 arXiv:
 arXiv:grqc/0612032
 Bibcode:
 2007JETPL..85....1B
 Keywords:

 04.50.+h;
 04.70.s;
 95.36.+x;
 04.50.+h;
 04.70.s;
 95.36.+x;
 Gravity in more than four dimensions KaluzaKlein theory unified field theories;
 alternative theories of gravity;
 Physics of black holes;
 Dark energy;
 General Relativity and Quantum Cosmology;
 Astrophysics;
 High Energy Physics  Theory
 EPrint:
 8 pages, latex