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Publications associées (16)

We analyse volume-preserving actions of product groups on Riemannian manifolds. Under a natural spectral irreducibility assumption, we prove the following dichotomy: Either the action is measurably isometric, in which case there are at most two factors; or ...

2009

Stable classical groups and strongly torsion generated groups

Strongly torsion generated groups are those with a single normal generator, of arbitrary finite order. They are useful for realizing sequences of abelian groups as homology groups. Known examples include stable alternating groups and stable groups generate ...

2009

On Singular Poisson Sternberg Spaces

We obtain a theory of stratified Sternberg spaces thereby extending the theory of cotangent bundle reduction for free actions to the singular case where the action on the base manifold consists of only one orbit type. We find that the symplectic reduced sp ...

2009

One of the most fundamental objects in algebra is the group. There exist plenty of different groups. In the following article we consider some free abelian gorups, cyclic groups, free groups and fundamental groups as well as the products of groups and draw ...

2008

Amenable actions, free products and a fixed point property

Nicolas Monod

We investigate the class of groups admitting an action on a set with an invariant mean. It turns out that many free products admit such an action. We give a complete characterisation of such free products in terms of a strong fixed point property. ...

2007

Multiple twinning in cubic crystals is represented geometrically by a three-dimensional fractal and algebraically by a groupoid. In this groupoid, the variant crystals are the objects, the misorientations between the variants are the operations, and the Σ3 ...

2007

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