The Stochastic Gravitational-Wave Background from Primordial Black Holes in R-Symmetric $SU(5)$ Inflation

Understand

This study explores the realization of nonminimally coupled Higgs inflation in the context of no-scale supergravity, investigates the formation of primordial black holes, and examines the potential for observable proton decay within the framework of the R-symmetric $SU(5)$ model.

• For inflation, both single and multifield scenarios are investigated.
• The prediction of the single-field model for the tensor-to-scalar ratio, $r$, is approximately $10^{-3}$, and the scalar spectral index falls within Plank's 1$\sigma$ range.
• The running of the scalar spectral index, $-{dn_{s}}/{d\ln{k}}$, is approximately $10^{-4}$.