Cogalois Theory

This volume offers a systematic, comprehensive investigation of field extensions, finite or not, that possess a Cogalois correspondence. The subject is somewhat dual to the very classical Galois Theory dealing with field extensions possessing a Galois correspondence. Solidly backed by over 250 exercises and an extensive bibliography, this book presents a compact and complete review of basic field theory, considers the Vahlen-Capelli Criterion, investigates the radical, Kneser, strongly Kneser, Cogalois, and G-Cogalois extensions, discusses field extensions that are simultaneously Galois and G-Cogalois, and presents nice applications to elementary field arithmetic.

Toma Albu is Professor of Mathematics at Atilim University, Ankara, Turkey, and Bucharest University, Romania. His research interests involve ring theory, module theory, field theory, and algebraic number theory. Dr. Albu has authored or coauthored several books and more than 75 articles appearing in various international journals. He received the M.Sc. (1966) and Ph.D (1971) degrees from Bucharest University, Romania. He was a Humboldt Research Fellow at the Universities of Munich and Dusseldorf. Dr. Albu has also held Visiting Professor positions in Osaka, Padua, Milwaukee, Columbus, and Santa Barbara.