% IMPORTANT: The following is UTF-8 encoded. This means that in the presence % of non-ASCII characters, it will not work with BibTeX 0.99 or older. % Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or % “biber”. @PHDTHESIS{Braun:1013585, author = {Braun, Tobias}, othercontributors = {Nebe, Gabriele and Robertz, Daniel}, title = {{C}lifford orders}, school = {RWTH Aachen University}, type = {Dissertation}, address = {Aachen}, publisher = {RWTH Aachen University}, reportid = {RWTH-2025-05622}, pages = {1 Online-Ressource : Illustrationen}, year = {2025}, note = {Veröffentlicht auf dem Publikationsserver der RWTH Aachen University; Dissertation, RWTH Aachen University, 2025}, abstract = {The aim of this thesis is to investigate the properties of the Clifford algebra of a quadratic lattice over a Dedekind domain and its completions and to compare it with the properties of the Clifford algebra of its ambient quadratic space. The new object that arises this way - the Clifford order - has not yet been studied extensively as an independent object. The present thesis addresses this, using both the theory of orders and Clifford algebras to extend well-known results that hold for Clifford algebras over fields to this new, more general setting. It was long known to theory that the centraliser of the even Clifford algebra, the so-called centroid is a cornerstone for describing the Clifford algebra of an orthogonal direct sum of quadratic spaces. This thesis develops the theory of quadratic orders, to describe the centroids of Clifford orders on an abstract level. In this context, a new invariant of a quadratic lattice, the quadratic discriminant, is introduced, allowing for a simplified computation of the centroids in certain situations. As applications, the centroids of the maximal lattices over a Dedekind domain and of an arbitrary root lattice are computed, and an effective way to determine the Clifford order of the orthogonal direct sum of two quadratic lattices is presented. Additionally, an algorithm to compute the centroid of a given Clifford orders over an arbitrary Dedekind domain is described. Finally, this thesis classifies the Clifford orders and the centroids of all maximal lattices over a complete discrete valuation ring and describes them as a subalgebra of their ambient Clifford algebra.}, cin = {114820 / 110000}, ddc = {510}, cid = {$I:(DE-82)114820_20140620$ / $I:(DE-82)110000_20140620$}, pnm = {DFG project G:(GEPRIS)286237555 - TRR 195: Symbolische Werkzeuge in der Mathematik und ihre Anwendung (286237555)}, pid = {G:(GEPRIS)286237555}, typ = {PUB:(DE-HGF)11}, doi = {10.18154/RWTH-2025-05622}, url = {https://publications.rwth-aachen.de/record/1013585}, }