Publications associées à Cohomologie de Weil

The cohomology of semi-simple Lie groups, viewed from infinity

We prove that the real cohomology of semi-simple Lie groups admits boundary values, which are measurable cocycles on the Furstenberg boundary. This generalises known invariants such as the Maslov index on Shilov boundaries, the Euler class on projective sp ...

2022

Isogeny graphs of ordinary abelian varieties

Dimitar Petkov Jetchev, Benjamin Pierre Charles Wesolowski, Ernest Hunter Brooks

Fix a prime number l. Graphs of isogenies of degree a power of l are well-understood for elliptic curves, but not for higher-dimensional abelian varieties. We study the case of absolutely simple ordinary abelian varieties over a finite field. We analyse gr ...

Springer Heidelberg2017

Some remarks on orbit sets of unimodular rows

Jean Fasel

Let A be a d-dimensional smooth algebra over a perfect field of characteristic not 2. Let Um(n+1)(A)/En+1 (A) be the set of unimodular rows of length n + 1 up to elementary transformations. If n >= (d + 2)/2, it carries a natural structure of group as disc ...

2011

Infinitesimal thickenings of Morava K-theories

A. Baker has constructed certain sequences of cohomology theories which interpolate between the Johnson-Wilson and the Morava K-theories. We realize the representing sequences of spectra as sequences of MU-algebras. Starting with the fact that the spectra ...

2008

Local properties of the Hochschild cohomology of C*-algebras

Let A be a C*-algebra, and let X be a Banach A-bimodule. Johnson [B. E. Johnson, 'Local derivations on C*-algebras are derivations', Trans. Amer Math. Soc. 353 (2000), 313-325] showed that local derivations from A into X are derivations. We extend this con ...

Cambridge University Press2008