Inspired by the Weierstrass representation of smooth affine minimal surfaces with indefinite metric, we propose a constructive process producing a large class of discrete surfaces that we call discrete affine minimal surfaces. We show that they are critical points of an affine area functional defined on the space of quadrangular discrete surfaces. The construction makes use of asymptotic coordi...

A general framework for anisotropic diffusion of multivalued images is presented. We propose an evolution equation where, at each point in time, the directions and magnitudes of the maximal and minimal rate of change in the vector-image are first evaluated. These are given by eigenvectors and eigenvalues of the first fundamental form in the given image metric. Then, the image diffuses via a sys...

We introduce a concept of 2 3 PROP generalizing the Kontsevich concept of 1 2 PROP. We prove that some Stasheff-type compactification of the Kontsevich spaces K(m,n) defines a topological 2 3 PROP structure. The corresponding chain complex is a minimal model for its cohomology (both are considered as 2 3 PROPs). We construct a 2 3 PROP End(V ) for a vector space V . Finally, we construct a dg L...

Let k an algebraically closed field, P the n-dimensional projective space over k and TPn the tangent vector bundle of P . In this paper I prove the following result : for every integer l, for every non-negative integer s, if Zs is the union of s points in sufficiently general position in P, then the restriction map H(P, TPn(l)) → H 0(Zs, TPn(l)|Zs) has maximal rank. This result implies that the...