Quintic surfaces of having a non singular model with
If denotes the variety of irreducible plane curves of degree with exactly nodes as singularities, Diaz and Harris (1986) have conjectured that is a torsion group. In this note we study rational equivalence on some families of singular plane curves and we prove, in particular, that is a finite group, so that the conjecture holds for . Actually the order of is , the group being cyclic if is odd and the product of and a cyclic group of order if is even.
We study some geometric configurations related to projections of an irreducible algebraic curve embedded in onto embedded projective planes. These configurations are motivated by applications to static and dynamic computational vision. More precisely, we study how an irreducible closed algebraic curve embedded in , of degree and genus , can be recovered using its projections from points onto embedded projective planes. The embeddings are unknown. The only input is the defining equation of...
The aim of this short survey is to give a quick introduction to the Salvetti complex as a tool for the study of the cohomology of Artin groups. In particular we show how a spectral sequence induced by a filtration on the complex provides a very natural and useful method to study recursively the cohomology of Artin groups, simplifying many computations. In the last section some examples of applications are presented.
The theory of Schur and Schubert polynomials is revisited in this paper from the point of view of generalized Thom polynomials. When we apply a general method to compute Thom polynomials for this case we obtain a new definition for (double versions of) Schur and Schubert polynomials: they will be solutions of interpolation problems.