Experimental limits on the free parameters of higher-derivative gravity

Understand

Fourth-derivative gravity has two free parameters, $\alpha$ and $\beta$, which couple the curvature-squared terms $R^2$ and $R_{\mu\nu}^2$.

• Relativistic effects and short-range laboratory experiments can be used to provide upper limits to these constants.
• In this work we briefly review both types of experimental results in the context of higher-derivative gravity.
• The strictest limit follows from the second kind of test.