Author(s): Peter D. Drummond, Alexander S. Dellios, and Margaret D. Reid We introduce coherent matrix phase-space distributions. These use conservation laws and symmetries to improve the accuracy and speed of quantum phase-space representations. As an example, this is applied to the validation of low-loss Gaussian boson sampling (GBS) quantum computational advantage expe… [Phys. Rev. Lett. 136, 013601] Published Tue Jan 06, 2026