STATE-SPACE IN BRST-QUANTIZATION AND KUGO-OJIMA QUARTETS

The structure of the state space in the BRST-quantization is considered and the connection between different approaches to the proof of the positive-definiteness of the metric on the physical state space is established. The correspondence between different expressions for the BRST-charge, quadratic in fields, is obtained. The relation between different representations of the BRST-algebra is found.