Evolution of dark energy perturbations in scalar-tensor cosmologies

Journal Article · Sat May 15 00:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.103505· OSTI ID:21413442

Bueno Sanchez, J C; Perivolaropoulos, L ^[1]

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1. Department of Physics, University of Ioannina, Ioannina (Greece)

We solve analytically and numerically the generalized Einstein equations in scalar-tensor cosmologies to obtain the evolution of dark energy and matter linear perturbations. We compare our results with the corresponding results for minimally coupled quintessence perturbations. We find that scalar-tensor dark energy density perturbations are amplified by a factor of about 10{sup 4} compared to minimally coupled quintessence perturbations on scales less than about 1000 h{sup -1} Mpc (sub-Hubble scales). On these scales dark energy perturbations constitute a fraction of about 10% compared to matter density perturbations. Scalar-tensor dark energy density perturbations are anticorrelated with matter linear perturbations on sub-Hubble scales. This anticorrelation of matter with negative pressure perturbations induces a mild amplification of matter perturbations by about 10% on sub-Hubble scales. The evolution of scalar field perturbations on sub-Hubble scales is scale independent and therefore corresponds to a vanishing effective speed of sound (c{sub s{Phi}=}0). We briefly discuss the observational implications of our results, which may include predictions for galaxy and cluster halo profiles that are modified compared to {Lambda}CDM. The observed properties of these profiles are known to be in some tension with the predictions of {Lambda}CDM.

• OSTI ID: 21413442
• Journal Information: Physical Review. D, Particles Fields, Vol. 81, Issue 10; Other Information: DOI: 10.1103/PhysRevD.81.103505; (c) 2010 The American Physical Society; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLIFICATION
ANALYTICAL SOLUTION
COMPARATIVE EVALUATIONS
COSMOLOGY
DENSITY
DISTURBANCES
EINSTEIN FIELD EQUATIONS
EVOLUTION
FORECASTING
GALAXIES
MAXIMUM PERMISSIBLE CONCENTRATION
NONLUMINOUS MATTER
NUMERICAL SOLUTION
PERTURBATION THEORY
SCALAR FIELDS
SOUND WAVES
VELOCITY
EQUATIONS
EVALUATION
FIELD EQUATIONS
MATHEMATICAL SOLUTIONS
MATTER
PHYSICAL PROPERTIES
SAFETY STANDARDS
STANDARDS