On the $(\beta )$-distortion of some infinite graphs

We show a distortion lower bound of $\mathrm{\Omega }(\log (h{)}^{1\mathrm{/}p})$ when embedding the countably branching hyperbolic tree of height $h$ into a Banach space with an equivalent norm satisfying Rolewicz property $(\beta )$ with modulus of power type $p>1$. Similarly we show that a distortion lower bound of $\mathrm{\Omega }(l^{1\mathrm{/}p})$ is incurred when embedding the parasol graphs with $l$ levels into a Banach space with the above property. We discuss the optimality of our results as well as several applications.