Early acceleration and adiabatic matter perturbations in a class of dilatonic dark-energy models

Abstract

We estimate the growth of matter perturbations in a class of recently proposed dark-energy models based on the (loop-corrected) gravi-dilaton string effective action, and characterized by a global attractor epoch in which dark-matter and dark-energy density scale with the same effective equation of state. Unlike most dark-energy models, we find that the accelerated phase might start even at redshifts as high as z~5 (thus relaxing the coincidence problem), while still producing at present an acceptable level of matter fluctuations. We also show that such an early acceleration is not in conflict with the recently discovered supernova SN1997ff at z~1.7 . The comparison of the predicted value of sigma_{8} with the observational data provides interesting constraints on the fundamental parameters of the given model of dilaton-dark matter interactions.

17 pages, 3 figures, uses RevTeX4, corrected some typos

References in corpus (14)

• A measurement by BOOMERANG of multiple peaks in the angular power spectrum of the cosmic microwave background
• Big-Bang Nucleosynthesis Predictions for Precision Cosmology
• Quintessence as a run-away dilaton
• Violations of the equivalence principle in a dilaton-runaway scenario
• A High Spatial Resolution Analysis of the MAXIMA-1 Cosmic Microwave Background Anisotropy Data
• Runaway dilaton and equivalence principle violations
• Stationary dark energy: the present universe as a global attractor
• Baryon bias and structure formation in an accelerating universe
• Testing the Cosmic Coincidence Problem and the Nature of Dark Energy
• Stationary dark energy with a baryon-dominated era: solving the coincidence problem with a linear coupling
• Large-N bounds on, and compositeness limit of, gauge and gravitational interactions
• Natural Quintessence and Large Extra Dimensions
• Structure Formation and the Time Dependence of Quintessence
• Dilatonic Interpretation of the Quintessence?

Cited by in corpus (17)

• Dilatonic ghost condensate as dark energy
• Linear and non-linear perturbations in dark energy models
• N-body simulations for coupled dark energy: halo mass function and density profiles
• Acceleration at z>1?
• Phantom energy mediates a long-range repulsive force
• Fitting Type Ia supernovae with coupled dark energy
• CMB Anisotropies in the Presence of Extra Dimensions
• Quintessence From The Decay of a Superheavy Dark Matter
• SNLS data are consistent with acceleration at z=3
• Dark Energy, Scalar-Tensor Gravity and Large Extra Dimensions
• Neutrino Dark Energy and Moduli Stabilization in a BPS Braneworld Scenario
• Discriminating different models of luminosity-redshift distribution
• Strongly Coupled Dark Energy Cosmologies yielding large mass Primordial Black Holes
• Dark Matter & Dark Energy from a single scalar field: CMB spectrum and matter transfer function
• Non-local dilaton coupling to dark matter: cosmic acceleration and pressure backreaction
• The Cosmological Supersymmetron
• A Faster Growth of Perturbations in an Early Matter Dominated Epoch: Primordial Black Holes and Gravitational Waves