Biswas, Indranil; Wong, Michael Lennox

The Universal Connection for Principal Bundles over Homogeneous Spaces and Twistor Space of Coadjoint Orbits

Doc. Math. 23, 77-115 (2018)
DOI: 10.25537/dm.2018v23.77-115


Given a holomorphic principal bundle $Q\longrightarrow X$, the universal space of holomorphic connections is a torsor $C_1(Q)$ for ${ad}\, Q\otimes T^\ast X$ such that the pullback of $Q$ to $C_1(Q)$ has a tautological holomorphic connection. When $X= G/P$, where $P$ is a parabolic subgroup of a complex simple group $G$, and $Q$ is the frame bundle of an ample line bundle, we show that $C_1(Q)$ may be identified with $G/L$, where $L \subset P$ is a Levi factor. We use this identification to construct the twistor space associated to a natural hyper-Kähler metric on $T^\ast(G/P)$, recovering Biquard's description of this twistor space, but employing only finite-dimensional, Lie-theoretic means.

Mathematics Subject Classification

14M17, 32L25, 32L10


$\lambda$-connection, rational homogeneous space, twistor space, complexification, Levi subgroup


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Biswas, Indranil
School of Mathematics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
Wong, Michael Lennox
Universität Duisburg-Essen, Fakultät für Mathematik, Thea-Leymann-Str. 9, 45127 Essen, Germany