We consider the Hurwitz zeta function zeta(s, a), and form two parts zeta(+) and zeta(-) by symmetric and antisymmetric combinations of zeta(s, a) and zeta(s, 1-a). We consider the properties of zeta(+) and zeta(-), and ...

We discuss general properties of doubly periodic sums over the square lattice, linking phased, Bloch-type sums in the direct lattice with displaced sums in the reciprocal lattice using the Poisson summation formula. We ...