E. Freitag

activity

19982025

most citedModular forms for the even unimodular lattice of signature (2,10)

12 citations · 30 across the 17 of their papers we have counts for

collaborators

23 papers

math.NT2025

Siegel modular forms of level (4,8) and weight two

Eberhard Freitag, Riccardo Salvati Manni

We consider the space of Siegel modular forms of genus $g$ of weight two relative to the main congruence subgroup of level 2 and to Igusa's group $Γ_{g} (4, 8)$ and $Γ_{g} (2, 4)$ .One of…

math.AG2025

Some remarks to a Theorem of van Geemen

Riccardo Salvati Manni, Eberhard Freitag

In [ Ge], Bert van Geemen computed the dimension of the space of the fourth power of the theta nullwerte. In [SM2], it has been observe that all linear relations between the $θ_m^4…

math.NT2022

Modular forms on SU(2,1) with weight $\frac{1}{3}$

Eberhard Freitag, Richard M. Hill

In this note, we describe several new examples of holomorphic modular forms on the group SU(2,1). These forms are distinguished by having weight $\frac{1}{3}$ . We also describe a m…

math.NT2020

Multiplier systems for Hermitian modular groups

Eberhard Freitag

Let $Γ_{F, n}$ be the Hermitian modular group of degree $n > 1$ in sense of Hel Braun with respect to an imaginary quadratic field $F$ . Let $r$ be a natural number. There exists a mul…

math.NT2020

Multiplier systems for Siegel modular groups

Eberhard Freitag, Adrian Hauffe Waschbüsch

Deligne proved that the weights of Siegel modular forms on any congruence subgroup of the Siegel modular group of genus g>1 must be integral or half integral. We give a different p…

math.AG2017

The Göpel variety