April 1,2020
Project leader:
Alfred Geroldinger
FWF project number:


Alfred Geroldinger, Ao.Univ.-Prof. Mag. Dipl.-Ing. Dr.
+43 (0)316 380 - 5154
Heinrichstraße 36, Room 526 (4th floor)
Qinghai Zhong, Dr.
+43 (0)316 380 - 5155
Heinrichstraße 36, Room 528 (4th floor)

All participants are located at the

Project summary

The present project is devoted to the ideal and module theory and to the arithmetic of (mainly commutative) noetherian domains, Mori domains, and Krull domains. Its main theme is factorization theory, in other words the study of the arithmetic of rings, of their semigroups of (invertible, divisorial, and other) ideals, and of semigroups of modules over these rings.

Let $H$ be a commutative monoid satisfying a weak cancellation property and the ascending chain condition on principal ideals. Then every non-invertible element has a factorization into irreducible elements, but in general there is no uniqueness. The main objective is to describe the various phenomena of non-uniqueness by arithmetical invariants (such as sets of lengths, catenary and tame degrees) and to study the interdependence of arithmetical invariants and classical algebraic invariants of the underlying algebraic structures. The following monoids are in the center of interest:

  • Transfer Krull monoids: they include all commutative Krull domains but also wide classes of non-commutative Dedekind domains.
  • Mori domains $R$ with nonzero conductor with respect to their complete integral closure.
  • Semigroups of ideals of the domains mentioned above.
  • Additive monoids of isomorphism classes of certain types of modules under direct sums.

    A key strategy runs as follows. Using ideal and module theory of the object $H$ one constructs a transfer homomorphism from $H$ to a simpler combinatorial object $B$. Transfer homomorphisms allow to pull back arithmetical information from $B$ to $H$. In case of a transfer Krull monoid $H$ the simpler object $B$ is a monoid of zero-sum sequences over an abelian group. Monoids of zero-sum sequences are studied with methods from additive combinatorics and, indeed, the project has a strong overlap with this area. The arithmetic of semigroups of ideals and modules, that are not cancellative, will be studied for the first time in a systematic way.


    1. A. Geroldinger, D. Grynkiewicz, Jun Seok Oh, and Qinghai Zhong
      On product-one sequences over dihedral groups.
    2. A. Geroldinger, F. Gotti and S. Tringali
      On strongly primary monoids with a focus on Puiseux monoids.
    3. Weidong Gao, Chao Liu, S. Tringali, and Qinghai Zhong
      On half-factoriality of transfer Krull monoids.
    4. Qinghai Zhong
      On an inverse problem of Erd\H{o}s, Kleitman, and Lemke.