The Limits of Extended Quintessence
| dc.creator | Nesseris, S. | |
| dc.creator | Perivolaropoulos, L. | |
| dc.date | 2006-11-07 | |
| dc.date | 2006-12-26 | |
| dc.date.accessioned | 2026-07-07T10:20:45Z | |
| dc.date.available | 2026-07-07T10:20:45Z | |
| dc.description | We use a low redshift expansion of the cosmological equations of extended (scalar-tensor) quintessence to divide the observable Hubble history parameter space in four sectors: A forbidden sector I where the scalar field of the theory becomes imaginary (the kinetic term becomes negative), a forbidden sector II where the scalar field rolls up (instead of down) its potential, an allowed `freezing' quintessence sector III where the scalar field is currently decelerating down its potential towards freezing and an allowed `thawing' sector IV where the scalar field is currently accelerating down its potential. The dividing lines between the sectors depend sensitively on the time derivatives of the Newton's constant G over powers of the Hubble parameter. For minimally coupled quintessence which appears as a special case for a constant G our results are consistent with previous studies. Observable parameter χ^2 contours based on current data (SNLS dataset) are also constructed on top of the sectors, for a prior of Ω_m=0.24. By demanding that the observed 2σχ^2 parameter contours do not lie entirely in the forbidden sectors we derive stringent constraints on the current second time derivative of Newton's constant G. In particular we find {\ddot G}/G >-1.91 H_0^2=-2 10^{-20}h^2 yrs^{-2} at the 2σlevel which is complementary to solar system tests which constrain only the first derivative of G as |{\dot G}/G|<10^{-14}yrs^{-1} at 1σ. | |
| dc.description | 9 pages (revtex), 5 figures. Accepted in Phys. Rev. D (to appear). The mathematica files of the analysis of the paper may be found at http://leandros.physics.uoi.gr/exqlim/exqlim.htm | |
| dc.identifier | https://arxiv.org/abs/astro-ph/0611238 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/0611238 | |
| dc.identifier | Phys.Rev.D75:023517,2007 | |
| dc.identifier | doi:10.1103/PhysRevD.75.023517 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/174951 | |
| dc.subject | Astrophysics | |
| dc.subject | General Relativity and Quantum Cosmology | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.subject | High Energy Physics - Theory | |
| dc.subject | Mathematical Physics | |
| dc.title | The Limits of Extended Quintessence | |
| dc.type | text |