It is well known that the continued fraction expansion of $\sqrt{D}$ readily displays the midpoint of the principal cycle of ideals, that is, the point halfway to a solution of $x^2-D{y}^2=\pm 1$. Here we notice that, analogously, the point halfway to a solution of $x^2-D{y}^2=-3$ can be recognised. We explain what is going on.

Let $f$ be a Hecke–Maass cusp form of eigenvalue $\lambda$ and square-free level $N$. Normalize the hyperbolic measure such that $\mathrm{vol}\left(Y_0\left(N\right)\right)=1$ and the form $f$ such that ${\parallel f\parallel }_2=1$. It is shown that ${\parallel f\parallel }_{\infty }{\ll }_{ϵ}{\lambda }^{\frac{5}{24}+ϵ}{N}^{\frac{1}{3}+ϵ}$ for all $ϵ>0$. This generalizes simultaneously the current best bounds in the eigenvalue and level aspects.

The purpose of this article is twofold. The first is to find the dimension of the set of integral points off divisors in subgeneral position in a projective algebraic variety $V\subset {\mathbb{P}}_{k̅}^m$, where k is a number field. As consequences, the results of Ru-Wong (1991), Ru (1993), Noguchi-Winkelmann (2003) and Levin (2008) are recovered. The second is to show the complete hyperbolicity of the complement of divisors in subgeneral position in a projective algebraic variety $V\subset {\mathbb{P}}_{ℂ}^m.$