Color-kinematics and double-copy relations for selfdual solutions

Abstract: We clarify the relation between the classical double copy and the double copy for amplitudes in the setting of selfdual gauge and gravity theories. To this end we construct explicit all-order perturbative solutions in these theories and show that they are related by a version of color-kinematics duality. This relation can be expressed in a double-copy form and embodies the most general manifestation of the selfdual classical double copy. Our classical double copy relations directly lead to known amplitude double-copy relations, both for Berends-Giele currents and on-shell amplitudes, through the perturbiner expansion.