Semidirect product

Adjoining a derivation

Let ๐”ค be a Lie algebra over ๐•‚ and ๐‘‘ be a derivation on ๐”ค. Then one may adjoin the derivation ๐‘‘ to ๐”ค by taking the semidirect product #m/def/lie

๐”คโ‹Š๐•‚๐‘‘

where ๐•‚๐‘‘ is the free vector space generated by ๐‘‘ with the unique (abelian) bracket.1

Special cases


#state/develop | #lang/en | #SemBr

Footnotes

  1. 1988. Vertex operator algebras and the Monster, ยง1.3, p. 8 โ†ฉ