Let Λ be a tubular canonical algebra of quiver type. We describe an algorithm, which for
numerical data computes all regular exceptional Λ-modules, or more generally all …

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 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 …

For standard algorithms verifying positive definiteness of a matrix $ A\in\mathbb {M} _n
(\mathbb {R}) $ based on Sylvester's criterion, the computationally pessimistic case is this …