TY - JOUR T1 - Local calibrations for minimizers of the Mumford-Shah functional with a triple junction JF - Commun. Contemp. Math. 4 (2002) 297-326 Y1 - 2002 A1 - Maria Giovanna Mora AB - We 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. PB - World Scientific UR - http://hdl.handle.net/1963/3050 U1 - 1283 U2 - Mathematics U3 - Functional Analysis and Applications ER -