We study the geometry of smooth non-homogeneous horospherical varieties of Picard rank
one. These have been classified by Pasquier and include the well-known odd symplectic …

We study the relation between torsion tensors of principal connections on G-structures and
characteristic conic connections on associated cone structures. We formulate sufficient …

We study the smooth projective symmetric variety of Picard number one that compactifies the
exceptional complex Lie group G2, by describing it in terms of vector bundles on the spinor …

We classify the pairs (C, G) where C is a seminormal curve over an arbitrary field k and G is
a smooth connected algebraic group acting faithfully on C with a dense orbit, and we …

We investigate families of minimal rational curves on Schubert varieties, their Bott–
Samelson desingularizations, and their generalizations constructed by Nicolas Perrin in the …

The works of Commichau--Grauert and Hirschowitz showed that a formal equivalence
between embeddings of a compact complex manifold is convergent, if the embeddings have …

Abstract The double Cayley Grassmannian is a unique smooth equivariant completion with
Picard number one of the 14-dimensional exceptional complex Lie group G 2, and it …

$\def\G {\overline {G}} $ For a complex connected semisimple linear algebraic group $ G $ of
adjoint type and of rank $ n $, De Concini and Procesi constructed its wonderful …

We describe varieties of minimal rational tangents on the wonderful symmetric varieties by
marked Dynkin diagrams. An irreducible component of a variety of minimal rational tangents …

Récemment, Kanemitsu a découvert un contre-exemple à la conjecture de longue date
selon laquelle le faisceau tangent d'une variété de Fano de nombre de Picard un est (semi) …