Connected weakly irreducible not irreducible subgroups of $\mbox {Sp}(1,n+1)\subset \mbox {SO}(4,4n+4)$ that satisfy a certain additional condition are classified. This will be used to classify connected holonomy groups of pseudo-hyper-Kählerian manifolds of index 4.
@article{127121, author = {Natalia I. Bezvitnaya}, title = {Weakly irreducible subgroups of $\mbox {Sp}(1,n+1)$}, journal = {Archivum Mathematicum}, volume = {044}, year = {2008}, pages = {341-352}, zbl = {1212.53071}, mrnumber = {2501571}, language = {en}, url = {http://dml.mathdoc.fr/item/127121} }
Bezvitnaya, Natalia I. Weakly irreducible subgroups of $\mbox {Sp}(1,n+1)$. Archivum Mathematicum, Tome 044 (2008) pp. 341-352. http://gdmltest.u-ga.fr/item/127121/
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