Cohomology, Homotopy, Extensions, and Automorphisms of Nijenhuis Lie Conformal Algebras
Sania Asif
TL;DR
The paper develops a comprehensive framework for Nijenhuis Lie conformal algebras by establishing a cohomology theory tied to deformation and extension problems. It introduces a two-tiered homotopy perspective via $2$-term ${\mathcal{L}}_\infty$-conformal algebras and shows skeletal cases correspond to $3$-cocycles while strict cases align with crossed modules. Non-abelian and abelian extension theories are classified through second cohomology groups, with a Wells-type map governing automorphism inducibility and yielding an exact sequence that reveals the interplay between automorphisms and cohomology. The results provide a rigorous toolkit for deformation, higher-homotopy structures, and extension problems in the conformal algebra setting, with potential implications for vertex algebras and conformal field theory.
Abstract
This paper explores various algebraic and homotopical aspects of Nijenhuis Lie conformal algebras, including their cohomology theory, $\mathcal{L}_\infty$-structures, non-abelian extensions, and automorphism groups. We define the cohomology of a Nijenhuis Lie conformal algebra and relate it to the deformation theory of such structures. We also introduce $2$-term Nijenhuis $\mathcal{L}_\infty$-conformal algebras and establish their correspondence with crossed modules and $3$-cocycles in the cohomology of Nijenhuis Lie conformal algebras. Furthermore, we develop a classification theory for non-abelian extensions of Nijenhuis Lie conformal algebras via the second non-abelian cohomology group. Finally, we study the inducibility problem for automorphisms under such extensions, introducing a Wells-type map and deriving an associated exact sequence.
