Non-linear spherical collapse in tachyon models, and a comparison of collapse in tachyon and quintessence models of dark energy

Abstract

We study evolution of perturbations in dark matter and dark energy for spherical collapse. We study Tachyon models of dark energy using the approach outlined in Rajvanshi and Bagla (2018). We work with models that are allowed by current observations. We find that as with Quintessence models allowed by observations, dark energy perturbations do not affect evolution of perturbations in dark matter in a significant manner. Perturbations in dark energy remain small for such models. In order to compare different classes of dark energy models, we use reconstruction of potentials and study dark matter and dark energy perturbations for same expansion history in the two models. We find that dark matter perturbations carry no imprint of the class of dark energy models for the same expansion history: this is significant in that we can work with any convenient model to study clustering of dark matter. We find that the evolution of dark energy perturbations carries an imprint of the class of models in that these grow differently in Tachyon models and Quintessence models. However, the difference between these diminishes for (1+w)<<1 and hence prospects for differentiating between models using characteristics of perturbations are limited in our Universe.

arXiv comment18 Pages, final (accepted) version

References in corpus (39)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• Dynamics of dark energy
• f(R) Theories Of Gravity
• Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models
• Modified Gravity and Cosmology
• The Confrontation between General Relativity and Experiment
• Modified Gravity Theories on a Nutshell: Inflation, Bounce and Late-time Evolution
• An alternative to quintessence
• Exploring the Expansion History of the Universe
• Accelerating Universes with Scaling Dark Matter
• A Dynamical Solution to the Problem of a Small Cosmological Constant and Late-time Cosmic Acceleration
• Essentials of k-essence
• Disappearing cosmological constant in f(R) gravity
• Tachyon Matter
• Accelerated expansion of the universe driven by tachyonic matter
• Reconstruction of a scalar-tensor theory of gravity in an accelerating universe
• A Precise Distance Indicator: Type Ia Supernova Multicolor Light Curve Shapes
• The Absolute Luminosities of the Calan/Tololo Type Ia Supernovae
• Cosmology with tachyon field as dark energy
• Beyond $\Lambda$CDM: Problems, solutions, and the road ahead
• Gravitational Wave Tests of General Relativity with Ground-Based Detectors and Pulsar Timing Arrays
• Can the clustered dark matter and the smooth dark energy arise from the same scalar field ?
• Dark Energy from structure: a status report
• Using SN Ia Light Curve Shapes to Measure The Hubble Constant
• Dark energy two decades after: Observables, probes, consistency tests
• Small scale problems of the $\Lambda$CDM model: a short review
• Observational Tests of Modified Gravity
• The core density of dark matter halos: a critical challenge to the Lambda-CDM paradigm?
• On virialization with dark energy
• Dark energy equation of state parameter and its variation at low redshifts
• Attractors and Isocurvature Perturbations in Quintessence Models
• Gauge-Invariant Initial Conditions and Early Time Perturbations in Quintessence Universes
• Scalar Field Dark Energy Perturbations and their Scale Dependence
• Low redshift observational constraints on tachyon models of dark energy
• Evolution of large-scale perturbations in quintessence models
• A comparison of perturbations in fluid and scalar field models of dark energy
• Nonlinear spherical perturbations in Quintessence Models of Dark Energy
• Reconstruction of Dynamical Dark Energy Potentials: Quintessence, Tachyon and interacting models

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• Spherical collapse of non-top-hat profiles in the presence of dark energy with arbitrary sound speed
• Dark energy model with very large-scale inhomogeneity
• Large-scale structure with superhorizon isocurvature dark energy
• Dynamics of tachyon dark energy on large scales and its imprint on observed galaxy power spectrum
• Spherical collapse in reconstructed dark energy models