Eugenia Roşu
Leiden University, Leiden, Netherlands

The Weierstrass $\pi$-function plays a great role in the classic theory of complex elliptic curves. A related function, the Weierstrass $\sigma$-function, is used by Guerzhoy to construct preimages under the $\xi$-operator of newforms of weight $2$, corresponding to elliptic curves. In this talk, I will discuss a generalization of the Weierstrass $\sigma$-function and an application to harmonic Maass forms. More precisely, I will describe a construction of a preimage of the $\xi$-operator of a newform of weight $k$ for $k$>$2$. This is based on joint work with C. Alfes-Neumann, J. Funke and M. Mertens.