MATHEMATISCHE NACHRICHTEN, cilt.290, sa.16, ss.2459-2511, 2017 (SCI-Expanded)
In this paper we establish square-function estimates on the double and single layer potentials for divergence form elliptic operators, of arbitrary even order 2m, with variable t-independent coefficients in the upper half-space. This generalizes known results for variable-coefficient second-order operators, and also for constant-coefficient higher-order operators.