-bundles and exotic actions
-cubes
Salvetti complex, spectral sequences and cohomology of Artin groups
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.
Sätze aus der Functionentheorie
Scalar curvature and connected sums of self-dual 4-manifolds
Under a reasonable vanishing hypothesis, Donaldson and Friedman proved that the connected sum of two self-dual Riemannian 4-manifolds is again self-dual. Here we prove that the same result can be extended to the positive scalar curvature case. This is an analogue of the classical theorem of Gromov–Lawson and Schoen–Yau in the self-dual category. The proof is based on twistor theory.
Scalar curvature, covering spaces, and Seiberg-Witten theory.
Scalar Curvature, Non-Abelian Group Actions, and the Degree of Symmetry of Exotic Spheres
Scalar curvature of defineable CAT-spaces.
Scharlemann's manifold is standard.
Schur and Schubert polynomials as Thom polynomials-cohomology of moduli spaces
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.
Schützenberger groups of some even degree polynomials in S(R).
Schwarzian derivative related to modules of differential operators on a locally projective manifold
We introduce a 1-cocycle on the group of diffeomorphisms Diff(M) of a smooth manifold M endowed with a projective connection. This cocycle represents a nontrivial cohomology class of Diff(M) related to the Diff(M)-modules of second order linear differential operators on M. In the one-dimensional case, this cocycle coincides with the Schwarzian derivative, while, in the multi-dimensional case, it represents its natural and new generalization. This work is a continuation of [3] where the same problems...
Scindement d’une équivalence d’homotopie en dimension
Scindements de Heegaard des espaces lenticulaires
Scindements de Hegaard et groupe de homéotopies des petites variétés de Seifert.
Search for different links with the same Jones' type polynomials: Ideas from graph theory and statistical mechanics
We describe in this talk three methods of constructing different links with the same Jones type invariant. All three can be thought as generalizations of mutation. The first combines the satellite construction with mutation. The second uses the notion of rotant, taken from the graph theory, the third, invented by Jones, transplants into knot theory the idea of the Yang-Baxter equation with the spectral parameter (idea employed by Baxter in the theory of solvable models in statistical mechanics)....
Second Chern class and Riemann-Roch for vector bundles on resolutions of surface singularities.
Second cohomology classes of the group of -flat diffeomorphisms
We study the cohomology of the group consisting of all -diffeomorphisms of the line, which are -flat to the identity at the origin. We construct non-trivial two second real cohomology classes and uncountably many second integral homology classes of this group.
Secondary characteristic classes for the isotropic Grassmannian
Secondary invariants for links