Some Remarks on Atypical Intersections

Abstract

In this paper we show how some known weak forms of the Zilber--Pink conjecture can be strengthened by combining them with the Mordell--Lang conjecture or its variants. We illustrate this idea by proving some theorems on atypical intersections in the semiabelian and modular settings. Given a "finitely generated" set $\Gamma$ with a certain structure, we consider $\Gamma$-special subvarieties -- weakly special subvarieties containing a point of $\Gamma$ -- and show that every variety $V$ contains only finitely many maximal $\Gamma$-atypical subvarieties, i.e. atypical intersections of $V$ with $\Gamma$-special varieties the weakly special closures of which are $\Gamma$-special.