Termination of the phase of quintessence by gravitational back reaction

We study the effects of gravitational back reaction in models of quintessence. The effective energy-momentum tensor with which cosmological fluctuations back react on the background metric will in some cases lead to a termination of the phase of acceleration. The fluctuations we make use of are the perturbations in our present Universe. Their amplitude is normalized by recent measurements of anisotropies in the cosmic microwave background; their slope is taken to be either scale invariant or characterized by a slightly blue tilt. In the latter case, we find that the back-reaction effect of fluctuations whose present wavelength is smaller than the Hubble radius but which are stretched beyond the Hubble radius by the accelerated expansion during the era of quintessence domination can become large. Since the back-reaction effects of these modes oppose acceleration, back reaction will lead to a truncation of the period of quintessence domination. This result impacts on the recent discussions of the potential incompatibility between string theory and quintessence.

[1]  O. Bertolami,et al.  A Two-Field Quintessence Model , 2001, astro-ph/0106405.

[2]  S. Schindler.  Ωm – Different Ways to Determine the Matter Density of the Universe , 2001, astro-ph/0107028.

[3]  W. Fischler,et al.  The Acceleration of the universe, a challenge for string theory , 2001 .

[4]  E. Witten.  Quantum Gravity In De Sitter Space , 2001, hep-th/0106109.

[5]  William J. Lahneman,et al.  Exponential Quintessence and the End of Acceleration , 2001, hep-ph/0105300.

[6]  J. Cline.  Quintessence, cosmological horizons, and self-tuning , 2001, hep-ph/0105251.

[7]  E. Halyo.  Hybrid Quintessence with an End or Quintessence from Branes and Large Dimensions , 2001, hep-ph/0105216.

[8]  Xiao-Gang He.  Accelerating Universe and Event Horizon , 2001, astro-ph/0105005.

[9]  L. Susskind,et al.  String theory and quintessence , 2001, hep-th/0104180.

[10]  R. Brandenberger.  Back Reaction of Cosmological Perturbations , 2000, hep-th/0004016.

[11]  M. White,et al.  STILL FLAT AFTER ALL THESE YEARS , 2000, astro-ph/0004003.

[12]  I. Hook,et al.  The Acceleration of the Universe: Measurements of Cosmological Parameters from Type Ia Supernovae , 2000 .

[13]  N. B. Suntzeff,et al.  Supernova Limits on the Cosmic Equation of State , 1998, astro-ph/9806396.

[14]  R. Brandenberger,et al.  The Energy - momentum tensor for cosmological perturbations , 1997, gr-qc/9704037.

[15]  R. Brandenberger,et al.  BACKREACTION PROBLEM FOR COSMOLOGICAL PERTURBATIONS , 1997 .

[16]  R. Brandenberger,et al.  On the Back Reaction Problem for Gravitational Perturbations , 1996, gr-qc/9609026.

[17]  Andrei Linde,et al.  Hybrid inflation. , 1993, Physical review. D, Particles and fields.

[18]  Hume A. Feldman,et al.  Theory of cosmological perturbations , 1992 .

[19]  P. Peebles,et al.  Cosmological consequences of a rolling homogeneous scalar field. , 1988, Physical review. D, Particles and fields.

[20]  C. Wetterich.  COSMOLOGY AND THE FATE OF DILATATION SYMMETRY , 1988, 1711.03844.

[21]  D. Lyth,et al.  Large-scale energy-density perturbations and inflation. , 1985, Physical review. D, Particles and fields.

[22]  R. Brandenberger,et al.  Cosmological perturbations in inflationary-universe models , 1984 .

[23]  Michael S. Turner,et al.  Spontaneous Creation of Almost Scale - Free Density Perturbations in an Inflationary Universe , 1983 .