We develop a general structure theory for compact homogeneous Riemannian manifolds in relation to the coindex of symmetry. We will then use these results to classify irreducible, simply connected, compact homogeneous ...

We show how to associate with each graph with a certain property (positivity) a family of simply connected solvable Lie groups endowed with left-invariant Riemannian metrics that are Ricci solitons (called solvsolitons). ...

Let N ⊂ M be a finite Jones' index inclusion of II1 factors and denote by UN ⊂ UM their unitary groups. In this article, we study the homogeneous space UM/UN, which is a (infinite dimensional) differentiable manifold, ...

Una ecuación especialmente sofisticada para evolucionar variedades casi-Kähler es el flujo de curvatura simpléctico, introducido por Streets-Tian. Los puntos fijos de este flujo, que reciben el nombre de estructuras ...

We prove the existence of an associated family of G-structure preserving minimal immersions into semi-Riemannian manifolds endowed with a compatible infinitesimally homogeneous G-structure. We will study in more details ...

For a given Hilbert space H, consider the space of self-adjoint projections P(H). In this paper we study the differentiable structure of a canonical sphere bundle over P(H) given by R={(P,f)∈P(H)×H:Pf=f,‖f‖=1}.We establish ...

In this paper we study the action of the symplectic operators which are a perturbation of the identity by a Hilbert-Schmidt operator in the Lagrangian Grassmannian manifold. We prove several geometric properties using the ...