Tropicalization is a non-Archimedean analytic stack quotient Ulirsch, Martin For a complex toric variety $X$ the logarithmic absolute value induces a natural retraction of $X$ onto the set of its non-negative points and this retraction can be identified with a quotient of $X(\mathbb{C})$ by its big real torus. We prove an analogous result in the non-Archimedean world: The Kajiwara-Payne tropicalization map is a non-Archimedean analytic stack quotient of $X^{an}$ by its big affinoid torus. Along the way, we provide foundations for a geometric theory of non-Archimedean analytic stacks, particularly focussing on analytic groupoids and their quotients, the process of analytification, and the underlying topological spaces of analytic stacks. 2014 info:eu-repo/semantics/preprint doc-type:preprint text http://purl.org/coar/resource_type/c_816b https://ris.uni-paderborn.de/record/66351 Ulirsch M. Tropicalization is a non-Archimedean analytic stack quotient. <i>arXiv:14102216</i>. Published online 2014. eng info:eu-repo/semantics/altIdentifier/arxiv/1410.2216 info:eu-repo/semantics/closedAccess