2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/35024The ADM Formalism is discussed in the context of 2+1--dimensional gravity, uniting two areas of relativity theory in which Stanley Deser has been particularly active. For spacetimes with topology R x T^2 the partially reduced and fully reduced ADM formalism are related and quantized, and the role of "large diffeomorphisms" (the modular group) in the quantum theory is illustrated.14 pages, 1 figure, to appear in Deserfest: A celebration of the life and works of Stanley Deser, Ann Arbor, Michigan, April 2004, (World Scientific)General Relativity and Quantum Cosmologytext