Gravity with higher-curvature terms and second-order field equations: f(R) meets Gauss-Bonnet
The episode discusses a paper detailing a new gravitational framework combining f(R) and Gauss-Bonnet terms. This mixed theory is not in Horndeski's class, allowing for complex physics. It modifies black hole geometry and offers structural improvements, such as suppressing Ricci scalar divergence in the interior.