Now showing 1 - 2 of 2
No Thumbnail Available
Publication

Automorphic properties of generating functions for generalized rank moments and Durfee symbols

2010, Bringmann, Kathrin, Lovejoy, Jeremy, Osburn, Robert

We define two-parameter generalizations of two combinatorial constructions of Andrews: the kth symmetrized rank moment and the k-marked Durfee symbol. We prove that three specializations of the associated generating functions are so-called quasimock theta functions, while a fourth specialization gives quasimodular forms. We then define a two-parameter generalization of Andrews' smallest parts function and note that this leads to quasimock theta functions as well. The automorphic properties are deduced using q-series identities relating the relevant generating functions to known mock theta functions.

No Thumbnail Available
Publication

Rank and crank moments for overpartitions

2009-07, Bringmann, Kathrin, Lovejoy, Jeremy, Osburn, Robert

We study two types of crank moments and two types of rank moments for overpartitions. We show that the crank moments and their derivatives, along with certain linear combinations of the rank moments and their derivatives, can be written in terms of quasimodular forms. We then use this fact to prove exact relations involving the moments as well as congruence properties modulo 3, 5, and 7 for some combinatorial functions which may be expressed in terms of the second moments. Finally, we establish a congruence modulo 3 involving one such combinatorial function and the Hurwitz class number H(n).