Displaying 21 – 40 of 76

Showing per page

The Mumford conjecture

Geoffrey Powell (2004/2005)

Séminaire Bourbaki

The Mumford Conjecture asserts that the rational cohomology of the stable moduli space of Riemann surfaces is a polynomial algebra on the Mumford-Morita-Miller characteristic classes; this can be reformulated in terms of the classifying space B Γ derived from the mapping class groups. The conjecture admits a topological generalization, inspired by Tillmann’s theorem that B Γ admits an infinite loop space structure after applying Quillen’s plus construction. The text presents the proof by Madsen and...

The rational homotopy type of configuration spaces of two points

Pascal Lambrechts, Don Stanley (2004)

Annales de l’institut Fourier

We prove that the rational homotopy type of the configuration space of two points in a 2 -connected closed manifold depends only on the rational homotopy type of that manifold and we give a model in the sense of Sullivan of that configuration space. We also study the formality of configuration spaces.

The Salvetti complex and the little cubes

Dai Tamaki (2012)

Journal of the European Mathematical Society

For a real central arrangement 𝒜 , Salvetti introduced a construction of a finite complex Sal ( 𝒜 ) which is homotopy equivalent to the complement of the complexified arrangement in [Sal87]. For the braid arrangement 𝒜 k - 1 , the Salvetti complex Sal ( 𝒜 k - 1 ) serves as a good combinatorial model for the homotopy type of the configuration space F ( , k ) of k points in C , which is homotopy equivalent to the space C 2 ( k ) of k little 2 -cubes. Motivated by the importance of little cubes in homotopy theory, especially in the study of...

Currently displaying 21 – 40 of 76