Singular integrals
Calderon-Zygmund kernels
L^2 estimate weak type L^1 estimate
Marcinkiewicz interpolation theorem - special case
Bessel and Riesz kernels
Sobolev spaces of fractional order
Characterization of Sobolev spaces in terms of Bessel potentials
Hilbert and Riesz transform
Poisson integral
Energies and potentials
Capacity
Singular integrals, spaces with fractional derivatives, characterization of Sobolev function by Bessel potentials, capacity