Quadratic forms associated with planar endomorphisms Academic Article uri icon


  • Any linear operator A on 2 is shown to have two real quadratic form on S1 associated with it. They represent the expansion and rotation of the map and the eigenvalues of A can be described in a geometrically intrinsic way in therms of the eigenvalues of these two quadratic forms via the formula .A number of theorems concerning these quadṙatic forms are presented.

publication date

  • December 2000