“…Partial results for the Cauchy problem are known in some situations, Date: January 25, 2022. The author was supported in part by NSF grants DMS-1911145 and DMS-2107938. including small data [1,16,18,30], monocharged and spherically-symmetric data [3,15,22], and lowerdimensional (d = 1, 2) settings [2,4,10,11,12,29]. These results all provide either time asymptotic growth estimates of characteristics or decay estimates of the electric field or charge density.…”