Structured sparsity regularization for gravitational- wave polarization reconstruction

Gravitational-wave (GW) observations with a network of more than two advanced detectors open the possibility of reconstructing the two polarizations predicted by General Relativity. We propose to address this problem using sparsity promoting regularizations. We consider a variety of techniques, including “structured sparsity” that allows to explicitly model the intrinsic clustering effect occurring in the time-frequency representation of GW transient signals. The proposed methods are evaluated with simulated GW signals and real-world noise. Numerical simulations show the advantages of the proposed approaches.