Seminarium "Teoria cząstek elementarnych i kosmologia"

Lensing is one of the classic tests of general relativity (GR). Recent work has shown how to employ scattering amplitudes in flat spacetime to derive the diffraction integral governing gravitational lensing and the resulting signal magnification. The formalism simplifies the calculation of higher-order post-Minkowskian corrections and wave-optics effects in gravitational lensing. It also naturally incorporates the spin and helicity of the scattered waves, as well as the effects of nonminimal gravitational interactions. In particular, it allows us to investigate polarization-dependent and helicity-changing effects. As an example, I will present the calculation of the lensing potential in the presence of higher-dimensional operators added to the GR Lagrangian. I will briefly discuss the potential experimental signatures of such operators and their detection prospects.