Memoirs of the American Mathematical Society 2002; 67 pp; softcover Volume: 159 ISBN10: 0821829343 ISBN13: 9780821829349 List Price: US$53 Individual Members: US$31.80 Institutional Members: US$42.40 Order Code: MEMO/159/754
 Koszul rings are graded rings which have played an important role in algebraic topology, algebraic geometry, noncommutative algebraic geometry, and in the theory of quantum groups. One aspect of the theory is to compare the module theory for a Koszul ring and its Koszul dual. There are dualities between subcategories of graded modules; the Koszul modules. When \(\Lambda\) is an artin algebra and \(T\) is a cotilting \(\Lambda\)module, the functor \(\mathrm{Hom}_\Lambda(\ ,T)\) induces a duality between certain subcategories of the finitely generated modules over \(\Lambda\) and \(\mathrm{End}_\Lambda(T)\). The purpose of this paper is to develop a unified approach to both the Koszul duality and the duality for cotilting modules. This theory specializes to these two cases and also contains interesting new examples. The starting point for the theory is a positively \(\mathbb{Z}\)graded ring \(\Lambda=\Lambda_0+\Lambda_1+\Lambda_2+\cdots\) and a (Wakamatsu) cotilting \(\Lambda_0\)module \(T\), satisfying additional assumptions. The theory gives a duality between certain subcategories of the finitely generated graded modules generated in degree zero over \(\Lambda\) on one hand and over the Yoneda algebra \(\oplus_{i\geq 0} \mathrm{Ext}^i_\Lambda(T,T)\) on the other hand. Readership Graduate students and research mathematicians interested in associative rings and algebras. Table of Contents  Main results and examples
 Proofs of main results
 Generalized \(T\)Koszul algebras
 Further results and questions
 Bibliography
