%0 Journal Article %T Natural symmetric tensor norms %A Daniel Carando %A Daniel Galicer %J Mathematics %D 2010 %I arXiv %R 10.1016/j.jmaa.2011.09.027 %X In the spirit of the work of Grothendieck, we introduce and study natural symmetric n-fold tensor norms. We prove that there are exactly six natural symmetric tensor norms for $n\ge 3$, a noteworthy difference with the 2-fold case in which there are four. We also describe the polynomial ideals associated to these natural symmetric tensor norms. Using a symmetric version of a result of Carne, we establish which natural symmetric tensor norms preserve Banach algebras. %U http://arxiv.org/abs/1002.3950v4