Inflation from Minkowski Space

Abstract

We propose a class of scalar models that, once coupled to gravity, lead to cosmologies that smoothly and stably connect an inflationary quasi-de Sitter universe to a low, or even zero-curvature, maximally symmetric spacetime in the asymptotic past, strongly violating the null energy condition ($\dot{H}\gg H^2$) at intermediate times. The models are deformations of the conformal galileon lagrangian and are therefore based on symmetries, both exact and approximate, that ensure the quantum robustness of the whole picture. The resulting cosmological backgrounds can be viewed as regularized extensions of the galilean genesis scenario, or, equivalently, as `early-time-complete' realizations of inflation. The late-time inflationary dynamics possesses phenomenologically interesting properties: it can produce a large tensor-to-scalar ratio within the regime of validity of the effective field theory and can lead to sizeable equilateral nongaussianities.

28+10 pages, 4 figures

References in corpus (12)

• Resummation of Massive Gravity
• The Effective Field Theory of Inflation
• Imperfect Dark Energy from Kinetic Gravity Braiding
• Starting the Universe: Stable Violation of the Null Energy Condition and Non-standard Cosmologies
• G-inflation: inflation driven by the Galileon field
• Galilean Genesis: an alternative to inflation
• Spontaneous breaking of Lorentz invariance, black holes and perpetuum mobile of the 2nd kind
• Resilience of the standard predictions for primordial tensor modes
• Subluminal Galilean Genesis
• Harrison--Zeldovich spectrum from conformal invariance
• DBI Realizations of the Pseudo-Conformal Universe and Galilean Genesis Scenarios
• Scalar tilt from broken conformal invariance

Cited by in corpus (7)

• The Effective Field Theory of nonsingular cosmology
• Stability of Geodesically Complete Cosmologies
• G-Bounce Inflation: Towards Nonsingular Inflation Cosmology with Galileon Field
• Relaxing the Cosmological Constant: a Proof of Concept
• Generalized Galilean Genesis
• Pre-inflationary primordial perturbations
• Scale-invariant perturbations from NEC violation: A new variant of Galilean Genesis