OPTIMAL HOMEOMORPHISMS BETWEEN CLOSED CURVES

The concept of natural pseudo-distance has proven to be a powerful tool for measuring the dissimilarity between topological spaces endowed with continuous real-valued functions. Roughly speaking, the natural pseudo-distance is defined as the infimum of the change of the functions' values, when moving from one space to the other through homeomorphisms, if possible. In this paper, we prove the first available result about the existence of optimal homeomorphisms between closed curves, i.e. inducing a change of the function that equals the natural pseudo-distance

On the stratication of secant varieties of Veronese varieties via symmetric rank.

When considering $\sigma_r(X)$, the variety of r-secant \PP {r-1} to a projective variety $X$, one question which arises is what are the possible values of the $X$-rank of points on $\sigma_r(X)$, apart from the generic value $r$? This geometric problem is of particular relevance (also for Applied Math) when $X$ is a variety parameterizing some kind of tensors. We study here the case when $X$ is a Veronese variety (i.e. the case of symmetric tensors). We find the complete description of the rank strata in some cases, and we give algorithms which compute the symmetric rank

Approximating the 2-dimensional matching distance

Some new approximation results about the 2-dimensional matching distance are presented, leading to the formulation of an algorithm for its computation (up to an arbitrary input error)