Shift-symmetric orbital inflation: single field or multi-field?
2019-06-17
12:00
UB
Aula 507 (Pere Pascual, ICCUB building, UB Campus)
Multi-field inflation with curved field manifold attracts a lot of attention recently. From a theoretical aspect, this class of models may be more naturally realized in the UV completion of inflation. From the observational point of view, however, the current constraints on primordial non-Gaussianity and isocurvature perturbation already/marginally ruled out many of these models.
In this talk, I will introduce a new class of two-field inflationary attractors, known as ‘shift-symmetric orbital inflation’. It is strongly multi-field, but the phenomenology still mimics single-field inflation with negligible amount of isocurvature modes and slow-roll suppressed non-Gaussianity, since in the end only one degree of freedom (the one with isocurvature origin) is responsible for the prediction of primordial perturbations. This new regime of multi-field attractors provides a different perspective to explore UV completion of inflation, which is free from the problems faced by single field models.