Heat semigroups on quantum automorphism groups of finite dimensional C*-algebras

In this paper, we investigate heat semigroups on a quantum automorphism group ${\mathrm{A}\mathrm{u}\mathrm{t}}^{+}(B)$ of a finite dimensional C*-algebra $B$ and its Plancherel trace. We show ultracontractivity, hypercontractivity, and the spectral gap inequality of the heat semigroups on ${\mathrm{A}\mathrm{u}\mathrm{t}}^{+}(B)$. Furthermore, we obtain the sharpness of the Sobolev embedding property and the Hausdorff-Young inequality of ${\mathrm{A}\mathrm{u}\mathrm{t}}^{+}(B)$.