Multi-field inflation and the field-space metric

TL;DR

This paper compares multi-field inflation models with different field-space metrics, analyzing how these metrics influence inflationary dynamics and observables, and establishing a duality between specific models.

Contribution

It introduces a unified framework for understanding spiral and Dante's inferno inflation models with nontrivial field-space metrics, linking single-field and multi-field descriptions.

Findings

Field-space metric significantly affects inflationary observables.

A duality exists between spiral inflation and Dante's inferno models.

A single-field effective description can be justified for these models.

Abstract

Multi-field inflation models include a variety of scenarios for how inflation proceeds and ends. Models with the same potential but different kinetic terms are common in the literature. We compare spiral inflation and Dante's inferno-type models, which differ only in their field-space metric. We justify a single-field effective description in these models and relate the single-field description to a mass-matrix formalism. We note the effects of the nontrivial field-space metric on inflationary observables, and consequently on the viability of these models. We also note a duality between spiral inflation and Dante's inferno models with different potentials.