2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/185578The projection of a two dimensional planar system on the higher Landau levels of an external magnetic field is formulated in the language of the non commutative plane and leads to a new class of star products.12 pages, latex, corrected versionHigh Energy Physics - TheoryCondensed Mattertext