**Phantom energy from graded algebras**

**Abstract:**

We construct a model of phantom energy using the graded Lie algebra SU(2/1). The negative kinetic energy of the
phantom field emerges naturally from the graded Lie algebra, resulting in an equation of state with w<-1. The model also
contains ordinary scalar fields and anti-commuting (Grassmann) vector
fields which can be taken as two component dark matter. A potential term is generated for both the phantom fields and the
ordinary scalar fields via a postulated condensate of the Grassmann vector fields. Since the phantom energy and dark matter
arise from the same Lagrangian the phantom energy and dark matter of this model are coupled via the Grassman vector fields.
In the model presented here phantom energy and dark matter come from a gauge principle rather than being introduced in an
ad hoc manner.