T-Model Inflation and Bouncing Cosmology

Abstract

We examine the dynamics of a closed cosmology whose matter source is that of a conformally coupled scalar field with a broken $\mathrm{SO}(1,1)$ symmetry, which correspond to the $\alpha$-attractors proposed by Linde and Kallosh. Following a field redefinition, such models give rise to "T-model" inflationary potentials, whose dynamics provide both an inflationary phase and a classical bounce. We show that the universe can undergo bounces far from the regime of quantum gravity. We analyse perturbations on this background with particular attention given to the effects of a double-bouncing scenario (with rapid recollapse between bounces) on the long wavelength modes. We demonstrate that the predictions of such models agree well with observations and might explain the suppression of power in the low multiples of the CMB.

29 pages, 7 figures

References in corpus (10)

• The Unity of Cosmological Attractors
• The Measure Problem in Cosmology
• Ultra slow-roll inflation demystified
• Inflationary schism after Planck2013
• Planck, LHC, and $\alpha$-attractors
• Matter creation in a nonsingular bouncing cosmology
• No fifth force in a scale invariant universe
• Black hole formation in a contracting universe
• Bouncing Universe from Nothing
• Inflation beyond T-models and primordial B-modes