Lie algebroid connection and Harder-Narasimhan reduction
Algebraic Geometry
2026-01-27 v1
Abstract
Take a holomorphic Lie algebroid on a compact connected Riemann surface such that the anchor map is not surjective. Let be a parabolic subgroup of a complex reductive affine algebraic group and a holomorphic reduction of structure group, to , of a holomorphic principal --bundle on . We prove that admits a holomorphic Lie algebroid connection for if the reduction is infinitesimally rigid. If is the Harder--Narasimhan reduction of , then it is shown that admits a holomorphic Lie algebroid connection for . In particular, for any point , the Harder--Narasimhan reduction admits a logarithmic connection that is nonsingular on the complement .
Keywords
Cite
@article{arxiv.2601.18169,
title = {Lie algebroid connection and Harder-Narasimhan reduction},
author = {Ashima Bansal and Indranil Biswas and Pradip Kumar},
journal= {arXiv preprint arXiv:2601.18169},
year = {2026}
}
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11 pages