Singular Degenerations of Lie Supergroups of Type $D(2,1;a)$

Kenji Iohara, Fabio Gavarini

The complex Lie superalgebras $\mathfrak{g}$ of type $D(2,1;a)$ - also denoted by $\mathfrak{osp}(4,2;a)$ - are usually considered for "non-singular" values of the parameter $a$,…