TY - JOUR AU - Métivier, Guy TI - $L^2$ well-posed Cauchy problems and symmetrizability of first order systems JO - Journal de l’École polytechnique — Mathématiques PY - 2014 SP - 39 EP - 70 VL - 1 PB - Ecole polytechnique UR - http://www.numdam.org/articles/10.5802/jep.3/ DO - 10.5802/jep.3 LA - en ID - JEP_2014__1__39_0 ER -