Speaker
Description
We study exact non-vacuum solutions of infinite derivative gravity (IDG). IDG is a ghost-free non-local theory of gravity, quadratic in curvature, whose field equations are highly convoluted. First, we employ the so-called almost universal spacetimes as an ansatz reducing IDG field equations to a single non-local but linear equation which is exactly solvable. This procedure allows us to obtain non-local analogues of Aichelburg–Sexl and Hotta–Tanaka solutions which represent gravitational waves generated by null sources propagating in Minkowski, de Sitter or anti-de Sitter backgrounds. Then, we step out the class of almost universal spacetimes and focus on axially symmetric type III pp-waves. This ansatz admits gyratonic sources and reduces IDG field equations to a partly linear and decoupled set of two ordinary differential equations. It turns out that with a Gaussian beam of the spinning null matter, this system is still completely solvable and provides an exact gyratonic solution of IDG.
