Infinitely conserved currents and hidden symmetry algebra related to the Belinskil-Zakharov's formulation of gravity

Based on the Belinskil-Zakharov (BZ) formulation of the vacuum Einstein equation with the metric gsub(ab) depending only on two coordinates, the related infinitely conserved currents are discussed. It is shown that there appears a set of nonlocal conservation currents which can be regarded as a parametric Noether current which arises from 'H-transformation'. By combining the transformation with BZ's L-A pair the GxC(t) algebraic structure in BZ's gravitational formulation is derived. (Auth.)