%0 Journal Article %T The Cayley Grassmannian %+ Institut de Mathématiques de Marseille (I2M) %A Manivel, Laurent %< avec comité de lecture %@ 0021-8693 %J Journal of Algebra %I Elsevier %8 2018-06 %D 2018 %Z 1602.02127 %R 10.1016/j.jalgebra.2018.02.010 %K octonion %K Cayley algebra %K Fano manifold %K spherical variety %K Schubert class %Z Mathematics [math]/Algebraic Geometry [math.AG]Journal articles %X We study the projective variety CG parametrizing four dimensional subalgebras of the complex octonions, which we call the Cayley Grass-mannian. We prove that it is a spherical G2-variety with only three orbits that we describe explicitely. Its cohomology ring has a basis of Schubert type classes and we determine the intersection product completely. %G English %2 https://hal.science/hal-01269989/document %2 https://hal.science/hal-01269989/file/cayleygrass2.pdf %L hal-01269989 %U https://hal.science/hal-01269989 %~ CNRS %~ UNIV-AMU %~ EC-MARSEILLE %~ I2M %~ I2M-2014-