PBH discriminants for modified gravity models

Determine whether primordial black hole mass spectra and statistical properties generated in f(R), f(T), f(Q), and mimetic gravity can be observationally distinguished—via gravitational-wave signatures or microlensing—and assess whether scalar-induced stochastic gravitational-wave backgrounds constitute unique fingerprints of specific modified gravity inflationary scenarios.

Background

The paper emphasizes that many modified gravity models can enhance small-scale scalar perturbations, potentially producing PBHs and associated scalar-induced gravitational waves. However, it remains unclear how to distinguish model classes observationally using PBH mass distributions and GW features.

Identifying robust discriminants would enable multi-messenger tests of early-universe gravity beyond the CMB.