Now showing items 6-13 of 13

    • Hereditary crossed products 

      Haefner, Jeremy; Janusz, Gerald (American Mathmatical Society, 2000-03-27)
      We characterize when a crossed product order over a maximal order in a central simple algebra by a finite group is hereditary. We need only concentrate on the cases when the group acts as inner automorphisms and when ...
    • The Isomorphism problem for incidence rings 

      Abrams, Gene; Haefner, Jeremy; Del Rio, Angel (University of California, 1999)
      Let P and P’ be finite preordered sets, and let R be a ring for which the number of nonzero summands in a direct decomposition of the regular module RR is bounded. We show that if the incidence rings I(P;R) and I(P’;R) ...
    • Isomorphisms of row and column finite matrix rings 

      Haefner, Jeremy; Del Rio, A.; Simon, J. (American Mathmatical Society, 1997-06)
      This paper investigates the ring-theoretic similarities and the cate- gorical dissimilarities between the ring RFM(R) of row finite matrices and the ring RCFM(R) of row and column finite matrices. For example, we prove ...
    • Local orders whose lattices are direct sums of ideals 

      Haefner, Jeremy (American Mathematical Society, 1990-10)
      Let R be a complete local Dedekind domain with quotient field K and let A be a local R-order in a separable K-algebra. This paper classifies those orders A such that every indecomposable R-torsionfree A-module is isomorphic ...
    • Mind over matter: Transforming course management systems into effective learning environments 

      Carmean, Colleen; Haefner, Jeremy (EDUCAUSE, 2002-12)
      Integrating best practices for "deeper learning" with the robust tools provided by course management systems creates an incredibly effective, engaging, and student-centered learning environment.
    • On when a graded ring is graded equivalent to a crossed product 

      Haefner, Jeremy (American Mathmatical Society, 1996-04)
      Let R be a ring graded by a group G. We are concerned with describing those G-graded rings that are graded equivalent to G-crossed products. We give necessary and sufficient conditions for when a strongly graded ring ...
    • Strongly graded hereditary orders 

      Haefner, Jeremy; Pappacena, Christopher (2001-08-28)
      Let R be a Dedekind domain with global quotient field K. The purpose of this note is to provide a characterization of when a strongly graded R-order with semiprime 1-component is hereditary. This generalizes earlier work ...