Geometric Structure of Multi-Form-Field Isotropic Inflation and Primordial Fluctuations [CL]

http://arxiv.org/abs/2201.03160


An inflationary scenario is expected to be embedded into an ultraviolet (UV) complete theory such as string theory. Quasi-heavy fields are ubiquitous in UV complete theory. The effect of these heavy fields may appear as nontrivial kinetic terms in the low energy effective field theory, which provides a nontrivial geometry in field space. In this paper, we study the effect of the geometry of multi-form-field space on an inflationary scenario. In particular, we focus on the geometric destabilization mechanism which induces the phase transition from the conventional slow-roll inflation to a novel inflationary scenario. Anisotropic inflation is a typical example of the new phase. To conform to observations, we restrict us to isotropic configuration of form fields. We clarify the conditions for the onset of the destabilization and reveal the geometric structure of attractors after the destabilization. We classify the viable models from the observational point of view. We also investigate the features of the primordial fluctuations and find the similarity to hyperbolic inflation. By calculating the power spectrum, we make several phenomenological predictions which are useful to discriminate our models from others inflation models.

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C. Chen and J. Soda
Tue, 11 Jan 22
58/95

Comments: 44 pages, 10 figures