Signatures of Multi-field Inflation in LISA

Unlike light, gravitational waves effectively propagate freely at all times. This will allow gravitational wave detectors like LISA to open a new, deeper window into the early universe. Cosmic inflation and other primordial dynamics could source a stochastic background of gravitational waves (SGWB) in the LISA band.

In this talk, I'll describe the known SGWB possibilities from two-field inflation, and discuss how adding a third field can change them.

The predicted stochastic backgrounds are sensitive to the path of the inflationary trajectory and the masses of the fields, and will provide new insights into the inflationary era even in the event of a non-detection.