• Best rank-k approximations for tensors: generalizing Eckart-Young 

      Tocino Sánchez, Alicia (2020-02-03)
      Joint work with Jan Draisma and Giorgio Ottaviani. Given a tensor f in a Euclidean tensor space, we are interested in the critical points of the distance function from f to the set of tensors of rank at most k, which we ...
    • Realisability problems in Algebraic Topology 

      Mendez Martinez, David (UMA Editorial, 2020-02-24)
      Realisability problems in Algebraic Topology are very easy to state and extremely hard to solve. Three classic examples of this are: the realisability of cohomology algebras, proposed by N. E. Steenrod in the 1960s, which ...