Incidence Algebras

This work covers the maximal and prime ideals of the incidence algebra, derivations and isomorphisms, radicals and additional ring-theoretic properties. Combinatorial discussions include a study of the Mobius function, reduced incidence subalgebras, and the coalgebra approach to incidence algebras.

This work covers the maximal and prime ideals of the incidence algebra, derivations and isomorphisms, radicals and additional ring-theoretic properties. Combinatorial discussions include a study of the Mobius function, reduced incidence subalgebras, and the coalgebra approach to incidence algebras.;College or university bookstores may order five or more copies for a special student price, which is available on request from Marcel Dekker.

Incidence algebras and coalgebras of lower finite quasi-ordered sets are characterized abstractly.

The Seventh ARTA (“Advances in Representation Theory of Algebras VII”) conference took place at the Instituto de Matemáticas of the Universidad Nacional Autónoma de México, in Mexico City, from September 24–28, 2018, in honor of José Antonio de la Peña's 60th birthday. Papers in this volume cover topics Professor de la Peña worked on, such as covering theory, tame algebras, and the use of quadratic forms in representation theory. Also included are papers on the categorical approach to representations of algebras and relations to Lie theory, Cohen–Macaulay modules, quantum groups and other algebraic structures.

The goal of this monograph is to develop Hopf theory in the setting of a real reflection arrangement. The central notion is that of a Coxeter bialgebra which generalizes the classical notion of a connected graded Hopf algebra. The authors also introduce the more structured notion of a Coxeter bimonoid and connect the two notions via a family of functors called Fock functors. These generalize similar functors connecting Hopf monoids in the category of Joyal species and connected graded Hopf algebras. This monograph opens a new chapter in Coxeter theory as well as in Hopf theory, connecting the two. It also relates fruitfully to many other areas of mathematics such as discrete geometry, semigroup theory, associative algebras, algebraic Lie theory, operads, and category theory. It is carefully written, with effective use of tables, diagrams, pictures, and summaries. It will be of interest to students and researchers alike.

The theory of algebras, rings, and modules is one of the fundamental domains of modern mathematics. General algebra, more specifically non-commutative algebra, is poised for major advances in the twenty-first century (together with and in interaction with combinatorics), just as topology, analysis, and probability experienced in the twentieth century. This is the second volume of Algebras, Rings and Modules: Non-commutative Algebras and Rings by M. Hazewinkel and N. Gubarenis, a continuation stressing the more important recent results on advanced topics of the structural theory of associative algebras, rings and modules.

The ICRA VII was held at Cocoyoc, Mexico, in August 1994. This was the second time that the ICRA was held in Mexico: ICRA III took place in Puebla in 1980. The 1994 conference included 62 lectures, all listed in these Proceedings. Not all contributions presented, however, appear in this book. Most papers in this volume are in final form with complete proofs, with the only exception being the paper of Leszczynski and Skowronski, Auslander algebras of tame representation type, that the editors thought useful to include.