# Classification of subspaces

Wild, M., Hermann, C., Moresi, R., Schuppli, R. 1998. Classification of subspaces, in Keller, H.A., Kunzi, U.-M., Wild, M. (eds.) Orthogonal geometry in infinite demensional vector spaces. Bayreuth : Mathematisches Institut der Universitat Bayreuth. 55-170.

Series -- Bayreuther mathematischen Schriften; Heft 53

Book Chapter

1.1 Statement of the problems and the lattice method Let E and E' be non-degenerate €-hermitean spaces over the same data (k, €, -) (see 1.1.1) with linear subspaces F and F', respectively. The.pairs (E, F) and (E', F') are isometric if there is an isometry <jJof E onto E' such that <jJF= F'. Isometry classification of pairs means reduction to the classification of spaces, the latter being a classical and often difficult problem even in finite dimensions.