6 papers
Complete homogeneous varieties over a field
Michel Brion, Matilde Maccan, Srinivasan Srimathy
The main objects of this paper are complete homogeneous varieties under the action of a semisimple group over field of characteristic . When the isotropy groups of the…
Horospherical subgroups in positive characteristic
Matilde Maccan, Ronan Terpereau
We investigate horospherical homogeneous spaces--a class of spherical homogeneous spaces encompassing both flag varieties and algebraic tori--over algebraically closed fields of ch…
Automorphism group of flag varieties with non-reduced stabilizer
Matilde Maccan
We consider rational projective homogeneous varieties over an algebraically closed field of positive characteristic, namely quotients of a semi-simple group by a possibly non-reduc…
Isotrivial elliptic surfaces in positive characteristic
Pascal Fong, Matilde Maccan
We study relatively minimal surfaces equipped with a strongly isotrivial elliptic fibration in positive characteristic by means of the notion of equivariantly normal curves introdu…
Parabolic subgroups in characteristics two and three
Matilde Maccan
This text brings to an end the classification of non-reduced parabolic subgroups in positive characteristic, especially two and three: they are all obtained as intersections of par…
Projective homogeneous varieties of Picard rank one in small characteristic
Matilde Maccan
We extend to characteristic and the classification of projective homogeneous varieties of Picard group isomorphic to , corresponding to parabolic subgroup schem…