In 2009, Keller and Yang categorified quiver mutation by interpreting it in
terms of equivalences between derived categories. Their approach was based on
Ginzburg's Calabi-Yau algebras and on Derksen-Weyman-Zelevinsky's mutation of
quivers with potential. Recently, Matthew Pressland has generalized mutation of
quivers with potential to that of ice quivers with potential. In this paper, we
show that his rule yields derived equivalences between the associated relative
Ginzburg algebras, which are special cases of Yeung's deformed relative
Calabi-Yau completions arising in the theory of relative Calabi-Yau structures
due to To\"en and Brav-Dyckerhoff. We illustrate our results on examples
arising in the work of Baur-King-Marsh on dimer models and cluster categories
of Grassmannians. We also give a categorification of mutation at frozen
vertices as it appears in recent work of Fraser-Sherman-Bennett on positroid
cluster structures.Comment: 34 pages; arXiv admin note: text overlap with arXiv:0906.0761,
arXiv:1810.01179 by other authors; many improvements and corrections;to
appear in Mathematische Zeitschrif