Poisson geometry and Azumaya loci of cluster algebras

There are two main types of objects in the theory of cluster algebras: the upper cluster algebras U with their Gekhtman- Shapiro-Vainshtein Poisson brackets and their root of unity quantizations U epsilon . On the Poisson side, we prove that (without any assumptions) the spectrum of every finitely generated upper cluster algebra U with its GSV Poisson structure always has a Zariski open orbit of symplectic leaves and give an explicit description of it. On the quantum side, we describe the fully Azumaya loci of the quantizations U epsilon under the assumption that A epsilon = U epsilon and U epsilon is a finitely generated algebra. All results allow frozen variables to be either inverted or not. (c) 2024 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.