Covariant and gauge-invariant linear scalar perturbations in multiple scalar field cosmologies

Abstract

We derive a set of equations monitoring the evolution of covariant and gauge-invariant linear scalar perturbations of Friedman-Lemaître-Robertson-Walker models with multiple interacting non-linear scalar fields. We use a dynamical systems' approach in order to perform a stability analysis for some classes of scalar field potentials. In particular, using a recent approximation for the inflationary dynamics of the background solution, we derive conditions under which homogenization occurs for chaotic (quadratic and quartic potentials) and new inflation. We also prove a cosmic no-hair result for power-law inflation and its generalisation for two scalar fields with independent exponential potentials (assisted power-law inflation).

42 pages, 32 figures

References in corpus (5)

• Dynamics of dark energy
• Inflationary Cosmology
• On the dynamics of a quadratic scalar field potential
• Late-time oscillatory behaviour for self-gravitating scalar fields
• Scalar Cosmological Perturbations

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• Inhomogeneous initial conditions for inflation: A wibbly-wobbly timey-wimey path to salvation
• Intermediate accelerated solutions as generic late-time attractors in a modified Jordan-Brans-Dicke theory
• A note on the dynamical system formulations in $f(R)$ gravity
• Robustness of inflation to kinetic inhomogeneities