We study the class of noncommutative theories in d dimensions whose spatial
coordinates (xi)i=1d can be obtained by performing a smooth change of
variables on (yi)i=1d, the coordinates of a standard noncommutative
theory, which satisfy the relation [yi,yj]=iθij, with a
constant θij tensor. The xi variables verify a commutation
relation which is, in general, space-dependent. We study the main properties of
this special kind of noncommutative theory and show explicitly that, in two
dimensions, any theory with a space-dependent commutation relation can be
mapped to another where that θij is constant.Comment: 21 pages, no figures, LaTeX. v2: section 5 added, typos corrected.
Version to appear in Physical Review