Renormalization and spectral representation in noncovariant gauges

An equation is obtained which directly connects the gluon propagator in noncovariant gauge with the gluon propagator in a special covariant gauge. In the αs2 order the connection is realized by the choice of the gauge α parameter in the form: αR*=-3(1+(5/6)2(αs/4π)N). The translation noninvariant spectral functions in noncovariant gauges are written in terms of the spectral function in covariant αR* gauge. The multiplicative renormalizability is realized in all orders of perturbation theory