2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/184959The concept of wave field is introduced to represent oriented media. The wave field is a tensor field of second rank, and directors are its eigenvectors. This exhibition of directors defines a natural gauge group inherit in continua and allows one to derive from variational principle general relativistic and gauge invariant equations for the wave field in question. Thus, the gauge-theoretical approach to continuum with internal degrees of freedom gives unambiguous and minimally coupled theory.LATeX, 9 pages, no figures and tablesGeneral Relativity and Quantum CosmologyCondensed Mattertext