Research PapersNo Access

COSMOLOGY WITH NEGATIVE POTENTIALS WITH w_ϕ<-1

Instituto de Física, UNAM, Apdo. Postal 20-364, 01000 México D.F., Mexico

and

Centro de Ciencias Físicas, Universidad Nacional Autónoma de México, Apartado Postal 48-3, 62251 Cuernavaca, Morelos, Mexico

Search for more papers by this author

https://doi.org/10.1142/S0218271804006061Cited by:11 (Source: Crossref)

Abstract

We study the cosmology of canonically normalized scalar fields that lead to an equation of state parameter of w_ϕ=p_ϕ/ρ_ϕ<-1 without violating the weak energy condition: ρ=Σ_iρ_i≥0 and ρ_i+p_i≥0. This kind of behavior requires a negative scalar potential V, widely predicted in particle physics. We show that the energy density ρ_ϕ=E_k+V takes negative values with an equation of state with w_ϕ<-1. However, the net effect of the ϕ field on the scale factor is to decelerate it giving a total equation of state parameter w=p/ρ>w_b=p_b/ρ_b, where ρ_b stands for any kind of energy density with -1≤w_b≤1, such as radiation, matter, cosmological constant or other scalar field with a potential V≥0. The fact that ρ_ϕ<0 allows, at least in principle, to have a small cosmological constant or quintessence today as the cancellation of high energy scales such as the electroweak or susy breaking scale. While V is negative |ρ_ϕ| is smaller than the sum of all other energy densities regardless of the functional form of the potential V. We show that the existence of a negative potential leads, inevitable, to a collapsing universe, i.e. to a would be "big crunch." In this picture we would still be living in the expanding universe.

Keywords:

You currently do not have access to the full text article.
Recommend the journal to your library today!

References

P. de Bernardis et al., Nature (London) 404, 955 (2000); S. Hannany et al., Astrophys. J. 545, L1 (2000) . Google Scholar
A. G. Riess et al., Astron. J. 116, 1009 (1998); S. Perlmutter et al., Astrophys. J. 517, 565 (1999); P. M. Garnavich et al., Astrophys. J. 509, 74 (1998) . Google Scholar
C. Baccigalupiet al., Phys. Rev. D65, 063520 (2002). Google Scholar
R. R. Caldwell, Phys. Lett. B545, 23 (2002). ADS, Google Scholar
B. McInnes, J. High Energy Phys. 0208, 029 (2002). ADS, Google Scholar
For an exhaustive list of reference see P. Singh, M. Sami and N. Dadhich, Phys. Rev. D68, 023522 (2003); J. M. Cline, S. Jeon and G. D. Moore, hep-ph/0311312 . Google Scholar
A. de la Macorra and H. Vuccetich, in preparation . Google Scholar
P. J. Steinhardt and N. Turok, Phys. Rev. D65, 126003 (2002). ADS, Google Scholar
J. Khouryet al., Phys. Rev. D64, 123522 (2001). ADS, Google Scholar
A. Linde, J. High Energy Phys. 0111, 052 (2001); N. Felder, A. V. Frolov, L. Kofman and A. V. Linde, Phys. Rev. D66, 023507 (2002) . Google Scholar
A. de la Macorra and C. Stephan-Otto, Phys. Rev. Lett. 87, 271301 (2001); Phys. Rev. D65, 083520 (2002) . Google Scholar
I. Zlatev, L. Wang and P. J. Steinhardt, Phys. Rev. Lett. 82, 8960 (1999); Phys. Rev. D59, 123504 (1999) . Google Scholar
A. de la Macorra, J. High Energy Phys. 0301, 033 (2003). ADS, Google Scholar
J. Garriga and A. Vilenkin, Phys. Rev. D61, 083502 (2000). Google Scholar
A. R. Liddle and R. J. Scherrer, Phys. Rev. D59, 023509 (1999). Google Scholar
A. de la Macorra and G. Piccinelli, Phys. Rev. D61, 123503 (2000). ADS, Google Scholar