A naive construction of motivic tubular neighborhoods

(Un exposé de Marc Levine au séminaire de théorie des nombres de Chevaleret le 13 juin 2005)

Résumé :

  Works of Spitzweck, Voevodsky, Ayoub and Roendigs have defined operations giving in particular an algebraic version of the classical constructions of a tubular neighborhood, and a punctured tubular neighborhood. We give another construction of tubular neighborhoods and show how this allows one to define algebraic invariants of the stable moduli spaces of smooth curves, such as motivic cohomology or algebraic K-theory.