Lie algebroid connection and Harder-Narasimhan reduction

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Authors: Ashima Bansal, Indranil Biswas, Pradip Kumar
Cited by: 0

Abstract

Take a holomorphic Lie algebroid $(V,\, ϕ)$ on a compact connected Riemann surface $X$ such that the anchor map $ϕ$ is not surjective. Let $P$ be a parabolic subgroup of a complex reductive affine algebraic group $G$ and $E_P\, \subset\, E_G$ a holomorphic reduction of structure group, to $P$, of a holomorphic principal $G$--bundle $E_G$ on $X$. We prove that $E_P$ admits a holomorphic Lie algebroid connection for $(V,\,ϕ)$ if the reduction $E_P$ is infinitesimally rigid. If $E_P$ is the Harder--Narasimhan reduction of $E_G$, then it is shown that $E_P$ admits a holomorphic Lie algebroid connection for $(V,\,ϕ)$. In particular, for any point $x_0\,\in\, X$, the Harder--Narasimhan reduction $E_P$ admits a logarithmic connection that is nonsingular on the complement $X\setminus\{x_0\}$.

Fields of Study & Subjects

Geometry and complex manifolds Algebraic Geometry and Number Theory Advanced Algebra and Geometry

Publication details

Journal / source
arXiv (Cornell University)
Publication date
26 January 2026
Document type
Preprint