Deformations and extensions of modified $λ$-differential $3$-Lie Algebras
Wen Teng, Hui Zhang
TL;DR
The work develops a cohomology framework for modified lambda-differential 3-Lie algebras with representations to control deformations and extensions. It defines adjoint and dual representations and builds a cochain complex whose cohomology groups, particularly the second group, govern deformation theory and extension classifications. Infinitesimal deformations correspond to 2-cocycles in the adjoint cohomology, with equivalence classes captured by the second cohomology; Nijenhuis and O-operators are introduced to produce trivial deformations and relate to semidirect products. The paper further provides a cohomology-based classification of abelian and T*-extensions and demonstrates how metrised structures arise from symmetry constraints on the cocycles, enabling construction of metrised extended algebras.
Abstract
In this paper, we introduce the representation of modified $λ$-differential $3$-Lie algebras and define the cohomology of modified $λ$-differential $3$-Lie algebras with coefficients in a representation. As applications of the proposed cohomology theory, we study linear deformations, abelian extensions and $T^*$-extensions of modified $λ$-differential $3$-Lie algebras.
