Ideal approximation in $n$-angulated categories

Abstract

We study ideal approximation theory associated to almost n-exact structures in extension closed subcategories of n-angulated categories. For n = 3, an n-angulated category is nothing but a classical triangulated category. Moreover, since every exact category can be embedded as an extension closed subcategory of a triangulated category, therefore, our approach extends the recent ideal approximations theories developed by Fu, Herzog et al. for exact categories and by Breaz and Modoi for triangulated categories.