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arXiv · 2102.09224

The ring of modular forms for the even unimodular lattice of signature (2,18)

Atsuhira Nagano·Kazushi Ueda
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Abstract

We show that the ring of modular forms with characters for the even unimodular lattice of signature (2,18) is obtained from the invariant ring of $\mathrm{Sym}(\mathrm{Sym}^8(V) \oplus \mathrm{Sym}^{12}(V))$ with respect to the action of $\mathrm{SL}(V)$ by adding a Borcherds product of weight 132 with one relation of weight 264, where $V$ is a 2-dimensional $\mathbb{C}$-vector space. The proof is based on the study of the moduli space of elliptic K3 surfaces with a section.

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Atsuhira Nagano, Kazushi Ueda. 2021-02-18. The ring of modular forms for the even unimodular lattice of signature (2,18). https://arxiv.org/abs/2102.09224

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