Katsoulis, Elias G.Ramsey, Christopher2020-12-112022-05-312022-05-312019Katsoulis, E. and C. Ramsey. (2019). Crossed products of operator algebras. American Mathematical Society. https://arxiv.org/abs/1512.08162978-1470435455https://hdl.handle.net/20.500.14078/2094We study crossed products of arbitrary operator algebras by locally compact groups of completely isometric automorphisms. We develop an abstract theory that allows for generalizations of many of the fundamental results from the selfadjoint theory to our context. We complement our generic results with the detailed study of many important special cases. In particular we study crossed products of tensor algebras, triangular AF algebras and various associated C°-algebras. We make contributions to the study of C°-envelopes, semisimplicity, the semi-Dirichlet property, Takai duality and the Hao-Ng isomorphism problem. We also answer questions from the pertinent literature.716.52KBPDFenAll Rights Reservedcrossed productJacobson Radicalsemicrossed productTakai dualityBookhttps://doi.org/10.48550/arXiv.1512.08162