title: Past and future blurring at fundamental length scale.
abstract: We obtain the κ-deformed versions of the retarded and advanced Green functions and show that their causality properties are blurred in a time interval of the order of a length parameter q=1/(2κ). The functions also indicate a smearing of the light cone. These results favor the interpretation of q as a fundamental length scale below which the concept of a point in space-time should be substituted by the concept of a fuzzy region of radius q, as proposed long ago by Heisenberg.
authors.affiliation: Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud 150, Urca, Rio de Janeiro, RJ, 22290-180, Brasil.
authors.forename: M J
authors.initials: MJ
authors.lastname: Neves
authors.forename: C
authors.initials: C
authors.lastname: Farina
authors.forename: M V
authors.initials: MV
authors.lastname: Cougo-Pinto