On two-dimensional Dirichlet spectrum

Renat Akhunzhanov, Denis Shatskov

We define two-dimensional Dirichlet spectrum (with respect to Euclidean norm) as D_2=λ\in\mathbf{R} | \exists \mathbf{v}=(v_1,v_2)\in \mathbf {R}^2: \limsup\limits_{t\rightarrow\in…