Generalized BRST transformation

The usual BRST transformations are characterized by an infinitesimal, anticommuting global parameter. Such transformations are symmetry of the effective action and nilpotent in nature. We have shown that it is possible to generalize BRST transformation by allowing the parameter to be field dependent and finite. Such extended BRST transformations also enjoy the same properties of usual BRST transformation as long as the parameter is space-time independent. However due to finiteness of the parameter such transformations do not leave the Jacobian of the path integral measure invariant. We have shown under certain condition the Jacobian can be made local functional of fields. Hence such generalized BRST transformation is capable of connecting the generating functional of two different effective theories. In this talk I will discuss construction, further extension and few applications of such finite field dependent BRST transformation.