Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 1805.08433

The Low-Dimensional Algebraic Cohomology of the Virasoro Algebra

Jill Ecker·Martin Schlichenmaier
View original source ↗Read source document ↗Export metadata ↓

Abstract

The main aim of this article is to prove the one-dimensionality of the third algebraic cohomology of the Virasoro algebra with values in the adjoint module. We announced this result in a previous publication with only a sketch of the proof. The detailed proof is provided in the present article. We also show that the third algebraic cohomology of the Witt and the Virasoro algebra with values in the trivial module is one-dimensional. We consider purely algebraic cohomology, i.e. our results are independent of any topology chosen. The vanishing of the third algebraic cohomology of the Witt algebra with values in the adjoint module has already been proven by Ecker and Schlichenmaier.

Explore related subjects

math.RAhep-thmath-phmath.MPmath.QA

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Jill Ecker, Martin Schlichenmaier. 2018-05-22. The Low-Dimensional Algebraic Cohomology of the Virasoro Algebra. https://doi.org/10.1088/1742-6596%2F1194%2F1%2F012032

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Normal Quaternionic Matrices and Finitely Generated Witt Rings

We present a new approach to verify the Elementary Type Conjecture for abstract Witt rings with small number of square classes. To do so, we make use of an abstract analogue of the 2-torsion part of the Brauer group. We develop a description of the entire structure of an abstract Witt ring with $2^n$ square classes in terms of a unique $n\times n$ matrix satisfying a small additional condition that particularly holds for Witt rings of fields. Via computational search, we find all these matrices for $n$ up to $7$. This verifies that all Witt rings of fields with up to $128$ square classes are of elementary type.

math.RA↗
arXiv2026

Graded differential polynomial rings

We study differential polynomial rings $R[t;δ]$ over $Γ$-graded rings, where $Γ$ is an arbitrary group. We show that $R[t;δ]$ admits a $Γ$-grading compatible with that of $R$ if and only if $δ$ is a $γ$-derivation for some $γ\in C_Γ(Γ_R)$, and that this grading is unique once $°(t)=γ$ is fixed; if $δ\neq0$, then $γ$ is itself uniquely determined by $δ$. We characterize the resulting graded ring by a universal property. We prove a characteristic-free center criterion for gr-simplicity whenever $Z(R[t;δ])$ is a graded subring; in characteristic zero, gr-simplicity is equivalent to $δ$-gr-simplicity of $R$ and $γ$-outerness of $δ$, extending Jordan's simplicity criterion to the graded setting. We further show that $R[t;δ]$ is gr-prime if and only if $R$ is $δ$-gr-prime, and that gr-Noetherianity of $R$ passes to $R[t;δ]$, recovering a graded Hilbert basis theorem as a special case. When $Γ$ is abelian, gr-simplicity and gr-primality are shown to be invariants of homogeneous graded Morita equivalence, and every ring homogeneously graded equivalent to $R[t;δ]$ via a compatible idempotent is again a graded differential polynomial ring.

math.RA↗
arXiv2026

Affinization of algebraic structures: Poisson algebras

An affinization of the notion of a Poisson algebra is presented. This is termed a Poisson affgebra and consists of an affine space together with an associative bi-affine multiplication and a bi-affine Lie bracket that acts as an affine derivation for the associative product. The constructive relation between Poisson affgebras and Poisson algebras is described and several low-dimensional examples are studied in detail.

math.RA↗