Corrigendum to: “A concrete analysis of the radical concept".
Corrigendum to: "Aspherical four-manifolds and the centres of two-knot groups".
Corrigendum to the paper " Quotient rings and one-sided primes".
Costable rings
Cotorsion modules for torsion theories
Cotorsion-free algebras as endomorphism algebras in - the discrete and topological cases
The discrete algebras over a commutative ring which can be realized as the full endomorphism algebra of a torsion-free -module have been investigated by Dugas and Göbel under the additional set-theoretic axiom of constructibility, . Many interesting results have been obtained for cotorsion-free algebras but the proofs involve rather elaborate calculations in linear algebra. Here these results are rederived in a more natural topological setting and substantial generalizations to topological...
Countably thick modules
The purpose of this paper is to further the study of countably thick modules via weak injectivity. Among others, for some classes of modules in we study when direct sums of modules from satisfies a property in . In particular, we get characterization of locally countably thick modules, a generalization of locally q.f.d. modules.
Counting equivalence classes of irreducible representations.
Counting solutions of decomposable form equations
Counting the number of elements in the mutation classes of -quivers.
Covering Spaces in Representation-Theory.
Coxeter Orbits and Eigenspaces of Frobenius
Coxeter polynomials of Salem trees
We compute the Coxeter polynomial of a family of Salem trees, and also the limit of the spectral radii of their Coxeter transformations as the number of their vertices tends to infinity. We also prove that if z is a root of multiplicities for the Coxeter polynomials of the trees respectively, then z is a root for the Coxeter polynomial of their join, of multiplicity at least where .
Criteria for shellable multicomplexes.
Critical Simply Connected Algebras.
CS-modules and annihilator conditions.
C(X) vs. C(X) modulo its socle
Let be the socle of C(X). It is shown that each prime ideal in is essential. For each h ∈ C(X), we prove that every prime ideal (resp. z-ideal) of C(X)/(h) is essential if and only if the set Z(h) of zeros of h contains no isolated points (resp. int Z(h) = ∅). It is proved that , where dim C(X) denotes the Goldie dimension of C(X), and the inequality may be strict. We also give an algebraic characterization of compact spaces with at most a countable number of nonisolated points. For each essential...
Cycle-finite algebras of semiregular type
We describe the structure of artin algebras for which all cycles of indecomposable finitely generated modules are finite and all Auslander-Reiten components are semiregular.
Cycle-finite algebras with almost all indecomposable modules of projective or injective dimension at most one
We describe the structure of artin algebras for which all cycles of indecomposable modules are finite and almost all indecomposable modules have projective or injective dimension at most one.
Cyclic Boolean algebras and Galois fields