Inflation from Anomalies

TL;DR

This paper reviews a string-inspired inflation model driven by gravitational wave condensates and Chern-Simons anomalies, highlighting mechanisms for chiral GW production and the role of axion potential modulations in achieving slow-roll inflation.

Contribution

It introduces a novel inflationary framework based on gravitational anomalies and chiral gravitational waves, integrating string theory concepts with cosmological inflation mechanisms.

Findings

Chiral gravitational waves can induce inflation through condensates.

Periodic modulations of the axion potential support slow-roll inflation.

The model aligns with key inflationary phenomenology constraints.

Abstract

We review a string-inspired model of inflation which is a consequence of condensates of chiral gravitational waves (GW) in the primordial Universe, leading in turn to a (approximately) constant condensate of a gravitational anomaly term of Chern-Simons (CS) type, present in the Lagrangian density that describes the dynamics of the very early Universe in the model. We discuss some mechanisms for the production of chiral GW, as well as the role of periodic modulations of the potential of the gravitational axion field, that couples to the CS anomaly term, in ensuring the correct inflationary slow-roll phenomenology of this model.