Electronic cash systems are used as payment tools of e-commerce. They should be
equipped with independence, transferability, and dividability, which are requirements of …

We study the complexity of Bongartz's algorithm for determining a maximal common direct
summand of a pair of modules M, N over k-algebra Λ; in particular, we estimate its …

We give a description of matrix bimodules parametrizing all indecomposable homogeneous
Λ-modules with a fixed integral slope over a tubular canonical algebra Λ, for all possible …

Let Λ be the four subspace algebra. We show that for any Λ-module M there exists an
algorithm (up to the problem of finding roots of the so-called characteristic polynomial of M) …

We give an algorithmic description of matrix bimodules parametrizing all indecomposable
homogeneous Λ-modules with a fixed slope q over a tubular canonical algebra Λ, for all …

We review our recent results concerning several computer algebra aspects of determining
canonical forms, performing a decomposition and deciding the isomorphism question for …

We present a general solution of the isomorphism and multiplicity problems, restricted to the
class of all modules lying in homogeneous tubes, for tame algebras (Theorem 2.4). We …

This thesis is devoted to the study of the geometry of representation spaces of string
algebras. For each irreducible component C of a representation space of a gentle string …

We prove that for any representation-finite algebra A (in fact, finite locally bounded k-
category), the universal covering F: Ã→ A is either a Galois covering or an almost Galois …