Euclidean Path Integral of the Gauge Field -- Holomorphic Representation
  Basing on the canonical quantization of a BRS invariant Lagrangian, we construct holomorphic representation of path integrals for Faddeev-Popov(FP) ghosts as well as for unphysical degrees of the gauge field from covariant operator formalism. A thorough investigation of a simple soluble gauge model with finite degrees will explain the metric structure of the Fock space and constructions of path integrals for quantized gauge fields with FP ghosts. We define fermionic coherent states even for a Fock space equipped with indefinite metric to obtain path integral representations of a generating functional and an effective action. The same technique will also be developed for path integrals of unphysical degrees in the gauge field to find complete correspondence, that insures cancellation of FP determinant, between FP ghosts and unphysical components of the gauge field. As a byproduct, we obtain an explicit form of Kugo-Ojima projection, $P^{(n)}$, to the subspace with $n$-unphysical particles in terms of creation and annihilation operators for the abelian gauge theory. 
Seiji Sakoda