Polynomial Szemerédi for sets with large Hausdorff dimension on the Torus

Let $\mathbb{P}=\{P_1,\cdots ,P_k\in \mathbb{R}[y]\}$ be a collection of polynomials with distinct degrees and zero constant terms. We proved that there exists $\epsilon =\epsilon (\mathbb{P})>0$ such that, for any compact set $E\subset \mathbb{T}$ with dim(E)$>1-\epsilon$, we can find $y\mathrm{\ne }0$ so that $\{x,x+P_1(y),\cdots ,x+P_k(y)\}\subset E$. The proof relies on a suitable version of the Sobolev smoothing inequality with ideas adapted from Peluse \cite{P19}, Durcik and Roos \cite{DR24}, and Krause, Mirek, Peluse, and Wright \cite{KMPW24}. As a byproduct of our Sobolev smoothing inequality, we demonstrated that the divergence set of the pointwise convergence problem for certain polynomial multiple ergodic averages has Hausdorff dimension strictly less than one.