Horizon-preserving dualities and perturbations in non-canonical scalar field cosmologies

Abstract

We generalize the cosmological duality between inflation and cyclic contraction under the interchange $a\leftrightarrow H$ to the case of non-canonical scalar field theories with varying speed of sound. The single duality in the canonical case generalizes to a family of three dualities constructed to leave the cosmological acoustic horizon invariant. We find three classes of models: (I) DBI inflation, (II) the non-canonical generalization of cyclic contraction, and (III) a new cosmological solution with rapidly decreasing speed of sound and relatively slowly growing scale factor, which we dub {\it stalled} cosmology. We construct dual analogs to the inflationary slow roll approximation, and solve for the curvature perturbation in all three cases. Both cyclic contraction and stalled cosmology predict a strongly blue spectrum for the curvature perturbations inconsistent with observations.

36 pages, LaTeX (v2: references added, version submitted to JCAP)

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Cited by in corpus (7)

• Quantum Circuit Complexity of Primordial Perturbations
• Pre-inflationary genesis with CMB B-mode polarization
• Galilean Islands in Eternally Inflating Background
• Consistency of Tachyacoustic Cosmology with de Sitter Swampland Conjectures
• The Trans-Planckian problem in Tachyacoustic Cosmology
• Attractor Solutions in Tachyacoustic Cosmology
• The four fixed points of scale invariant single field cosmological models