2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/53487It is shown that the quantum position operator of Newton and Wigner for non-zero mass systems is uniquely determined if one imposes a quantum ''manifest covariance'' condition of the same type as the similar condition of Currie, Jordan and Sudarshan in the the framework of the Hamiltonian formalism.10 pages, PLAIN-TEXHigh Energy Physics - TheoryOn the Uniqueness of the Newton-Wigner Position Operatortext