%0 Journal Article %A Jürgen Hausen %T A Hilbert–Mumford criterion for $SL_2$-actions %J Colloquium Mathematicum %D 2003 %P 151-161 %V 97 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/cm97-2-2/ %R 10.4064/cm97-2-2 %G en %F 10_4064_cm97_2_2