Abstract
We prove a generalisation of a theorem of Nagata on ruled surface to the case of the fiber bundle E/P → X, associated to a principal G-bundle E. Using this we prove boundedness for the isomorphism classes of semi-stable G-bundles in all characteristics.
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Holla, Y.I., Narasimhan, M.S. A Generalisation of Nagata's Theorem on Ruled Surfaces. Compositio Mathematica 127, 321–332 (2001). https://doi.org/10.1023/A:1017505213601
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DOI: https://doi.org/10.1023/A:1017505213601