Enveloping algebra identities on solutions of conformally invariant wave equations

We study identities in the enveloping algebra of the conformal group, which is the symmetry group of many wave equations: d'Alambert, Weyl, Maxwell, etc. We find all second-order identities for these equations and, in addition, the dimension of the space of nontrivial symmetry operators of any order for the d'Alambert equation.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 14–18, September, 1991.