Tilting pairs and Wakamatsu tilting pairs of subcategories over cleft extensions

Abstract

Let $(\mathcal{B},\mathcal{A}, i, e, l)$ be a cleft extension of abelian categories. We prove that the functor $l$ preserves and reflects (Wakamatsu) tilting pairs of subcategories under certain conditions, unifying an abundance of known results. Then, we apply our results to the cleft extensions of module categories, and give characterizations of tilting pairs and Wakamatsu tilting pairs over $θ$-extension of rings and tensor rings, which not only recover the earlier results in this direction, but also obtain some new conclusions.