On the Stability of Phantom K-essence Theories
Astrophysics
2009-11-13 v2 General Relativity and Quantum Cosmology
High Energy Physics - Theory
Abstract
We show that phantom dark energy, if it is described by a K-essence theory, has three fundamental problems: first, its hamiltonian is unbounded from below. Second, classical stability precludes the equation of state from crossing the ``Lambda-barrier'', . Finally, both the equation of state and the sound speed are unbounded -- the first, from below, the second, from above -- if the kinetic term is not bounded by dynamics.
Keywords
Cite
@article{arxiv.astro-ph/0511562,
title = {On the Stability of Phantom K-essence Theories},
author = {L. Raul Abramo and Nelson Pinto-Neto},
journal= {arXiv preprint arXiv:astro-ph/0511562},
year = {2009}
}
Comments
Replaced with accepted version (minor changes, 1 reference added). Revtex4, 4 pages (double column), 1 figure