33 citations · 90 across the 37 of their papers we have counts for
5 papers · 1 filter
Erratum: Some Remarks on the Cohomology of Krichever-Novikov Algebras
Friedrich Wagemann
We discovered that only a weakened version of the main lemma is true. We state the right version, and the remaining open problem: Is it possible to approximate holomorphic vector f…
On the Leibniz cohomology of vector fields
Alessandra Frabetti, Friedrich Wagemann
I. M. Gelfand and D. B. Fuks have studied the cohomology of the Lie algebra of vector fields on a manifold. In this article, we generalize their main tools to compute the Leibniz c…
A Crossed Module giving the Godbillon-Vey Cocycle
Friedrich Wagemann
We find crossed modules, i.e. certain 4 term exact sequences, associated to the Godbillon-Vey class for W_1, Vect(S^1), Vect_{1,0}(Σ) and Hol(Σ_r), i.e. for the Lie algebras of for…
A Two Dimensional Analogue of the Virasoro Algebra
Friedrich Wagemann
The author regrets that after discussion of the results with B. L. Feigin a serious error has shown up. The proof of the results we presented in the paper is wrong. We thank B. L.…
Explicit Formulae for Cocycles of Holomorphic Vector Fields with values in lambda-Densities
Friedrich Wagemann
We give explicit formulae for the generators of H^2(Hol(Σ_r,{\cal F}_λ(Σ_r)) in terms of affine and projective connections. This is done using the cocycles of V. Ovsienko and C. Ro…