R. Coquereaux, ON THE FINITE-DIMENSIONAL QUANTUM-GROUP M-3-CIRCLE-PLUS-(M-2 1(LAMBDA(2)))(0)/, letters in mathematical physics, 42(4), 1997, pp. 309-328
We describe a few properties of the nonsemisimple associative algebra
H = M-3 + (M-2/1(Lambda(2)))(0), where Lambda(2) is the Grassmann alge
bra with two generators. We show that H is not only a finite-dimension
al algebra but also a (noncommutative) Hopf algebra, hence a finite-di
mensional quantum group. By selecting a system of explicit generators,
we show how it is related with the quantum enveloping of SLq(2) when
the parameter q is a cubic root of unity. We describe its indecomposab
le projective representations as well as the irreducible ones. We also
comment about the relation between this object and the theory of modu
lar representation of the group St(2, F-3), i.e. the binary tetrahedra
l group. Finally, we briefly discuss its relation with the Lorentz gro
up and, as already suggested by A. Connes, make a few comments about t
he possible use of this algebra in a modification of the Standard Mode
l of particle physics (the unitary group of the semisimple algebra ass
ociated with H is U(3) x U(2) x U(1)).