An Upper Bound for the Dimension of Bounded Derived Categories

Let $\Lambda$ be an artin algebra. We give an upper bound for the dimension of the bounded derived category of the category $\mod \Lambda$ of finitely generated right $\Lambda$-modules in terms of the projective and injective dimensions of certain class of simple right $\Lambda$-modules as well as the radical layer length of $\Lambda$. In addition, we give an upper bound for the dimension of the singularity category of $\mod \Lambda$ in terms of the radical layer length of $\Lambda$.