Abstract
We provide an intrinsic definition of the fundamental group of a linear category over a ring as the automorphism group of the fibre functor on Galois coverings. If the universal covering exists, we prove that this group is isomorphic to the Galois group of the universal covering. The grading deduced from a Galois covering enables us to describe the canonical monomorphism from its automorphism group to the first Hochschild-Mitchell cohomology vector space.
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This work has been supported by the projects MATHAMSUD, UBACYTX212, PIP-CONICET 112-2000801-00487 and PICT-2007-02182 (ANPCyT). The second and third authors are research members of CONICET (Argentina) and the third author is a Regular Associate of ICTP Associate Scheme.
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Cibils, C., Redondo, M.J. & Solotar, A. The Intrinsic Fundamental Group of a Linear Category. Algebr Represent Theor 15, 735–753 (2012). https://doi.org/10.1007/s10468-010-9263-1
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DOI: https://doi.org/10.1007/s10468-010-9263-1