Right Coideal Subalgebras, Hopf Galois Objects, and $ı$-Hopf Algebras

Rongchuan Xiong

We study right comodule algebras and their connections with Hopf bi-Galois objects and right coideal subalgebras. For a Hopf $2$-cocycle $\sigma$ on $K$ and a unital right-colinear alge…