Abstract
In a semi-abelian category, we give a categorical construction of the push forward of an internal pre-crossed module, generalizing the pushout of a short exact sequence in abelian categories. The main properties of the push forward are discussed. A simplified version is given for action accessible categories, providing examples in the categories of rings and Lie algebras. We show that push forwards can be used to obtain the crossed module version of the comprehensive factorization for internal groupoids.
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Dedicated to George Janelidze on the occasion of his 60th birthday
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Cigoli, A.S., Mantovani, S. & Metere, G. A Push Forward Construction and the Comprehensive Factorization for Internal Crossed Modules. Appl Categor Struct 22, 931–960 (2014). https://doi.org/10.1007/s10485-013-9348-1
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DOI: https://doi.org/10.1007/s10485-013-9348-1