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arXiv · 1206.2711

Attractor Solutions in Tachyacoustic Cosmology

Dennis Bessada·William H. Kinney
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Abstract

We study the dynamical stability of "tachyacoustic" cosmological models, in which primordial perturbations are generated by a shrinking sound horizon during a period of decelerating expansion. Such models represent a potential alternative to inflationary cosmology, but the phase-space behavior of tachyacoustic solutions has not previously been investigated. We numerically evaluate the dynamics of two non-canonical Lagrangians, a cuscuton-like Lagrangian and a Dirac-Born-Infeld Lagrangian, which generate a scale-invariant spectrum of perturbations. We show that the power-law background solutions in both cases are dynamical attractors.

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Dennis Bessada, William H. Kinney. 2012-09-22. Attractor Solutions in Tachyacoustic Cosmology. https://doi.org/10.1103/physrevd.86.083502

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