Translators invariant under hyperpolar actions

Abstract

In this paper, we consider translators (for the mean curvature flow) given by a graph of a function on a symmetric space $G/K$ of compact type which is invariant under a hyperpolar action on $G/K$. First, in the case of $G/K=SO(n+1)/SO(n)$, $SU(n+1)/S(U(1)\times U(n))$, $Sp(n+1)/(Sp(1)\times Sp(n))$ or $F_4/{\rm Spin}(9)$, we classify the shapes of translators in $G/K\times\mathbb R$ given by the graphs of functions on $G/K$ which are invariant under the isotropy action $K\curvearrowright G/K$. Next, in the case where $G/K$ is of higher rank, we investigate translators in $G/K\times\mathbb R$ given by the graphs of functions on $G/K$ which are invariant under a hyperpolar action $H\curvearrowright G/K$ of cohomogeneity two.