3 papers
math.DG2019
Notes on flat pseudo-Riemannian manifolds
Fabricio Valencia
In these notes we survey basic concepts of affine geometry and their interaction with Riemannian geometry. We give a characterization of affine manifolds which has as counterpart t…
math.SG2019
Infinitesimally Tight Lagrangian Orbits
Elizabeth Gasparim, Luiz A. B. San Martin, Fabricio Valencia
We describe isotropic orbits for the restricted action of a subgroup of a Lie group acting on a symplectic manifold by Hamiltonian symplectomorphisms and admitting an Ad*-equivaria…
math.DG2019
Flat affine symplectic Lie groups
Fabricio Valencia
We give a new characterization of flat affine manifolds in terms of an action of the Lie algebra of classical infinitesimal affine transformations on the bundle of linear frames. W…