Download or read book Patching on Berkovich Spaces and the Local-Global Principle written by Vlere Mehmeti and published by . This book was released on 2019 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: Field patching, introduced by Harbater and Hartmann, and extended by the aforementioned authors and Krashen, has recently seen numerous applications. We present an extension of this technique to the setting of Berkovich analytic geometry and applications to the local-global principle.In particular, we show that this adaptation of patching can be applied to Berkovich analytic curves, and as a consequence obtain local-global principles over function fields of curves defined over complete ultrametric fields. Because of the connection between the points of a Berkovich analytic curve and the valuations that its function field can be endowed with, one of these local-global principles is given with respect to completions, thus evoking some similarity with more classical versions. As an application, we obtain local-global principles for quadratic forms and results on the u-invariant. These findings generalize those of Harbater, Hartmann and Krashen.As a starting point for higher-dimensional patching in the Berkovich setting, we show that this technique is applicable around certain fibers of a relative Berkovich analytic curve. As a consequence, we prove a local-global principle over the germs of meromorphic functions on said fibers. By showing that said germs of meromorphic functions are algebraic, we also obtain local-global principles over function fields of algebraic curves defined over a larger class of ultrametric fields.