A simultaneous approximation problem for exponentials and logarithms

Abstract

Let $\alpha_1,\alpha_2$ be non-zero algebraic numbers such that $\frac{\log \alpha_2}{\log\alpha_1}\notin\mathbb{Q}$ and let $\beta$ be a quadratic irrational number. In this article, we prove that the values of two relatively prime polynomials $P(x,y,z)$ and $Q(x,y,z)$ with integer coefficients are not too small at the point $\left(\frac{\log\alpha_2}{\log \alpha_1},\alpha_1^\beta, \alpha_2^\beta \right)$. We also establish a measure of algebraic independence of those numbers among $\frac{\log\alpha_2}{\log \alpha_1}$, $\alpha^\beta_1$ and $\alpha^\beta_2$ which are algebraically independent.