On multifractal formalism for self-similar measures with overlaps

Julien Barral, De-Jun Feng

Published 2020-02-06Version 1

Let $\mu$ be a self-similar measure generated by an IFS $\Phi=\{\phi_i\}_{i=1}^\ell$ of similarities on $\mathbb R^d$ ($d\ge 1$). When $\Phi$ is dimensional regular (see Definition~1.1), we give an explicit formula for the $L^q$-spectrum $\tau_\mu(q)$ of $\mu$ over $[0,1]$, and show that $\tau_\mu$ is differentiable over $(0,1]$ and the multifractal formalism holds for $\mu$ at any $\alpha\in [\tau_\mu'(1),\tau_\mu'(0+)]$. We also verify the validity of the multifractal formalism of $\mu$ over $[\tau_\mu'(\infty),\tau_\mu'(0+)]$ for two new classes of overlapping algebraic IFSs by showing that the asymptotically weak separation condition holds. For one of them, the proof appeals to a recent result of Shmerkin on the $L^q$-spectrum of self-similar measures.