Dynamical consistency conditions for rapid turn inflation

Abstract

We derive consistency conditions for sustained slow roll and rapid turn inflation in two-field cosmological models with oriented scalar field space, which imply that inflationary models with field-space trajectories of this type are non-generic. In particular, we show that third order adiabatic slow roll, together with large and slowly varying turn rate, requires the scalar potential of the model to satisfy a certain nonlinear second order PDE, whose coefficients depend on the scalar field metric. We also derive consistency conditions for slow roll inflationary solutions in the so called ``rapid turn attractor'' approximation, as well as study the consistency conditions for circular rapid turn trajectories with slow roll in two-field models with rotationally invariant field space metric. Finally, we argue that the rapid turn regime tends to have a natural exit after a limited number of e-folds.

39 pages; minor improvements, references and appendix added

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Cited by in corpus (9)

• The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
• (Slow-)Twisting inflationary attractors
• Non-Gaussianity in rapid-turn multi-field inflation
• On the Consistency of Rapid-Turn Inflation
• Generalised conditions for rapid-turn inflation
• Loops in inflation with strongly non-geodesic motion
• Hidden Symmetries, Rapid Turns and Cosmic Acceleration
• Consistency Condition for Slow-roll and Rapid-turn Inflation
• Infrared behavior in tame hyperbolizable two-field models