Earthquakes as Probing Tools for Gravity Theories

We propose a novel method for testing gravity models using seismic waves’ velocities. By imposing observational constraints on Earth’s moment of inertia and mass, we rigorously limit the gravitational models’ parameters within a 2σ accuracy. Our method, taking the PREM model as our reference and assuming its viability, constrains the parameters governing additional terms to the General Relativity Lagrangian to the following ranges: −2×109≲β≲109m2 for Palatini f(R) gravity, −8×109≲ϵ≲4×109m2 for Eddington-inspired Born–Infeld gravity, and −10−3≲Υ≲10−3 for Degenerate Higher-Order Scalar–Tensor theories. We also discuss potential avenues to enhance the proposed method, aiming to impose even tighter constraints on gravity models.