This paper introduces the notion of a quasi-ho
m-Lie algebra, or si
mply, a qhl-algebra, which is a natural generalization of ho
m-Lie algebras introduced in a previous paper [J.T.
Hartwig, D. Larsson, S.D. Silvestrov, Defor
mations of Lie algebras using
σ-derivations,
math.QA/0408064]. Quasi-ho
m-Lie algebras include also as special cases (color) Lie algebras and superalgebras, and can be seen as defor
mations of these by
maps, twisting the Jacobi identity and skew-sy
mmetry. The natural real
m for these quasi-ho
m-Lie algebras is generalizations-defor
mations of the Witt algebra
me=""mml1"">method=retrieve&_udi=B6WH2-4G35M6J-1&_mathId=mml1&_user=10&_cdi=6838&_rdoc=5&_handle=V-WA-A-W-WU-MsSAYWA-UUW-U-AAWCVWEYCY-AAWBUAUZCY-WCDBEWEZA-WU-U&_acct=C000050221&_version=1&_userid=10&md5=a2b1723403f41d53c9e38fc0563ee7c3"">mg src=""http://www.sciencedirect.com/cache/MiamiImageURL/B6WH2-4G35M6J-1-2/0?wchp=dGLbVzb-zSkzk"" alt=""Click to view the MathML source"" align=""absbottom"" border=""0"" height=11 width=10> of derivations on the Laurent polyno
mials
me=""mml2"">method=retrieve&_udi=B6WH2-4G35M6J-1&_mathId=mml2&_user=10&_cdi=6838&_rdoc=5&_handle=V-WA-A-W-WU-MsSAYWA-UUW-U-AAWCVWEYCY-AAWBUAUZCY-WCDBEWEZA-WU-U&_acct=C000050221&_version=1&_userid=10&md5=85c1851858d066c1a8d1a54342c36d97"">mg src=""http://www.sciencedirect.com/cache/MiamiImageURL/B6WH2-4G35M6J-1-3/0?wchp=dGLbVzb-zSkzk"" alt=""Click to view the MathML source"" align=""absbottom"" border=""0"" height=17 width=58>. We also develop a theory of central extensions for qhl-algebras which can be used to defor
m and generalize the Virasoro algebra by centrally extending the defor
med Witt type algebras constructed here. In addition, we give a nu
mber of other interesting exa
mples of quasi-ho
m-Lie algebras, a
mong the
m a defor
mation of the loop algebra.