Pseudo-Anosovs optimizing the ratio of Teichmüller to curve graph translation length

Abstract

Given $\varphi$ a pseudo-Anosov map, let ${\ell }_{\mathcal{T}}(\varphi )$ denote the translation length of $\varphi$ in the Teichmüller space, and let ${\ell }_{\mathcal{C}}(\varphi )$ denote the stable translation length of $\varphi$ in the curve graph. Gadre--Hironaka--Kent--Leininger showed that, as a function of Euler characteristic $\chi (S)$, the minimal possible ratio $\tau (\varphi )=\frac{{\ell }_{\mathcal{T}}(\varphi )}{{\ell }_{\mathcal{C}}(\varphi )}$ is $\log (|\chi (S)|)$, up to uniform additive and multiplicative constants. In this short note, we introduce a new construction of such ratio optimizers and demonstrate their abundance in the mapping class group. Further, we show that ratio optimizers can be found arbitrarily deep into the Johnson filtration as well as in the point pushing subgroup.

arXiv comment12 page, 1 figure