00836nas a2200109   4500008004300000245009200043210006900135260002100204520044000225100002500665856003600690       2002                        en_Ud  00aLocal calibrations for minimizers of the Mumford-Shah functional with a triple junction0 aLocal calibrations for minimizers of the MumfordShah functional   bWorld Scientific3 aWe prove that, if u is a function satisfying all Euler conditions for the Mumford-Shah functional and the discontinuity set of u is given by three line segments meeting at the origin with equal angles, then there exists a neighbourhood U of the origin such that u is a minimizer of the Mumford-Shah functional on U with respect to its own boundary conditions on the boundary of U. The proof is obtained by using the calibration method.1 aMora, Maria Giovanna  uhttp://hdl.handle.net/1963/3050