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Relations between categorifications of higher-dimensional type $A$ cluster combinatorics

Representation Theory 2026-05-27 v1 Combinatorics Category Theory

Abstract

We consider three categories arising from the higher Auslander algebras of type AA in relation to dd-dimensional cluster combinatorics: dd-exact subcategory of the module category of An+1dA^d_{n+1} generated by the dd-cluster-tilting object, the (d+2)(d+2)-angulated cluster category, and the dd-almost positive subcategory of the derived category (the higher analogue of the category of two-term complexes of projectives). We show that the third one, introduced by the second-named author, is the dd-exangulated quotient of the other two, introduced by Oppermann and Thomas, by the ideals generated by morphisms factoring through morphisms from injective to projective objects, thus providing an algebraic connection between the two models of Oppermann-Thomas. This is a dd-exangulated version in type AA of a result of Br\"ustle and Yang and its interpretation by the first-named author together with Fang, Palu, Plamondon and Pressland. It also explains a well-known coincidence between the number of 2-term silting complexes in type AnA_{n} and of tilting modules in type An+1A_{n+1} from the 00-Auslander perspective. We expect this to serve as a prototypical example of the 00-Auslander correspondence in higher homological algebra.

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Cite

@article{arxiv.2605.27263,
  title  = {Relations between categorifications of higher-dimensional type $A$ cluster combinatorics},
  author = {Mikhail Gorsky and Nicholas J. Williams},
  journal= {arXiv preprint arXiv:2605.27263},
  year   = {2026}
}

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13 pages