Invariants of Lie algebras extended over commutative algebras without unit

Abstract

We establish results about the second cohomology with coefficients in the trivial module, symmetric invariant bilinear forms and derivations of a Lie algebra extended over a commutative associative algebra without unit. These results provide a simple unified approach to a number of questions treated earlier in completely separated ways: periodization of semisimple Lie algebras (Anna Larsson), derivation algebras, with prescribed semisimple part, of nilpotent Lie algebras (Benoist), and presentations of affine Kac-Moody algebras.

v3: added a footnote on p.10 about a wrong derivation of the correct statement

References in corpus (1)

• Low-dimensional cohomology of current Lie algebras and analogs of the Riemann tensor for loop manifolds

Cited by in corpus (4)

• On $\delta$-derivations of Lie algebras and superalgebras
• A compendium of Lie structures on tensor products
• δ-derivations of semisimple structurable algebras
• Defining relations of almost affine (hyperbolic) superalgebras