Example: interpretation of Cartan complex

Let us consider the case:

The odd tangent bundle has a natural volume form. This induces a half-density on :

let the half-density on induced from the volume form on

It satisfies the Quantum Master Equation.

Now consider a different half-density, which also satisfies the Quantum Master Equation:

where is the BV Hamiltonian generating the lift to of the canonical odd vector field on .

We can replace with an arbitrary function of . This will still satisfy the Quantum Master Equation.

Suppose that a Lie group acts on . This action can be lifted to and . An infinitesimal action of on is generated by the BV Hamiltonian:

Therefore, in this case:

It satisfies Eq. (21):

This formula can be generalized as follows. Suppose that is a function on . For any , we think of as a function on , i.e. a pseudo-differential form on . With a slight abuse of notaions, will also denote the pullback of along the projection, from to . Then we have:

Therefore is an intertwiner from the Cartan complex to the complex of equivariant half-densities on .