TADEUSZ IWANIEC and JAN KRISTENSEN
A construction of quasiconvex functions
Received: 21 January 2005
Mathematics Subject Classification (2000): 49Nxx - 30C65 - 35J60
Abstract: We present an elementary method for constructing quasiconvex functions. It is based on the observation that given any suitably rank-1 convex function R and any strongly quasiconvex function P the function R+tP is quasiconvex for sufficiently large numbers t. The method is illustrated on a remarkable family of functions defined on real two-by-two matrices.