Local Newforms for GSp(4) describes a theory of new- and oldforms for
representations of GSp(4) over a non-archimedean local field. This
theory considers vectors fixed by the paramodular groups, and singles
out certain vectors that encode canonical information, such as L-factors
and epsilon-factors, through their Hecke and Atkin-Lehner eigenvalues.
While there are analogies to the GL(2) case, this theory is novel and
unanticipated by the existing framework of conjectures. An appendix
includes extensive tables about the results and the representation
theory of GSp(4).