Title: Porosity and regularity in metric measure spaces,
Abstract: This is a report of a joint work with E. Järvenpää, M. Järvenpää,
T. Rajala, S. Rogovin, and V. Suomala. In [3], we characterized uniformly
porous sets in $s$-regular metric spaces in terms of regular sets by verifying
that a set $A$ is uniformly porous if and only if there is $t < s$ and a
$t$-regular set $F \supset A$. Here we outline the main idea of the proof and
also present an alternative proof for the crucial lemma needed in the proof of
the result.