Sous-espaces équi-isoclins de l'espace euclidien

A systematic study of equi-isoclinic n-tuples of the Grassmann manifold G(d;N) is initiated. After basic results in the general case, the article focuses on the cased = 2. In particular the lists of all regular equi-isoclinic n-tuples of G(2; 2n) and of all equi-isoclinic quadruples of G(2; 6) are established.