The first three cohomology groups were introduced by Lichtenbaum & Schlessinger (1967) and are sometimes called Lichtenbaum–Schlessinger functors T0, T1, T2, and the higher groups were defined independently by Michel André and by Daniel Quillen using methods of homotopy theory.
De första tre kohomologigrupperna introducerades av Lichtenbaum & Schlessinger (1967) och kallas ibland Lichtenbaum–Schlessinger-funktorerna T0, T1, T2, och de högre grupperna definierades oberoende av Michel André och Daniel Quillen genom att använda homotopiteori.