eprintid: 8278 rev_number: 9 eprint_status: archive userid: 1 dir: disk0/00/00/82/78 datestamp: 2008-05-29 13:25:25 lastmod: 2015-04-23 21:15:34 status_changed: 2012-08-14 15:25:28 type: preprint metadata_visibility: show creators_name: Hardouin, Charlotte title: Iterative $q$-Difference Galois Theory ispublished: pub subjects: ddc-510 divisions: i-708000 cterms_swd: $q$-difference Galois theory cterms_swd: roots of unity cterms_swd: iterative operators abstract: Initially, the Galois theory of $q$-difference equations was built for $q$ unequal to a root of unity. This choice was made in order to avoid the increase of the field of constants to a transcendental field. Inspired by the work of B.H. Matzat and M. van der Put, we consider in this paper a family of iterative difference operators instead of considering just one difference operator, and in this way we stop the increase of the constant field and succeed in setting up a Picard-Vessiot theory for $q$-difference equations where $q$ is a root of unity that extend the Galois theory of difference equations of Singer and van der Put. The theory we obtain is quite the exact translation of the iterative differential Galois theory developed by B.H. Matzat and M. van der Put to the $q$-difference world. abstract_translated_lang: eng date: 2008 date_type: published id_scheme: DOI id_number: 10.11588/heidok.00008278 portal_cluster_id: p-iwrpp portal_order: 08278 ppn_swb: 1646787935 own_urn: urn:nbn:de:bsz:16-opus-82789 language: eng bibsort: HARDOUINCHITERATIVEQ2008 full_text_status: public series: IWR-Preprints citation: Hardouin, Charlotte (2008) Iterative $q$-Difference Galois Theory. [Preprint] document_url: https://archiv.ub.uni-heidelberg.de/volltextserver/8278/1/itaut7.pdf