% 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{Neunhffer:58877, author = {Neunhöffer, Max}, othercontributors = {Hiß, Gerhard}, title = {{U}ntersuchungen zu {J}ames' {V}ermutung über {I}wahori-{H}ecke-{A}lgebren vom {T}yp {A}}, address = {Aachen}, publisher = {Publikationsserver der RWTH Aachen University}, reportid = {RWTH-CONV-120704}, pages = {150 S.}, year = {2003}, note = {Aachen, Techn. Hochsch., Diss., 2003}, abstract = {This thesis deals with a conjecture by Gordon James from 1990 and a variant by Meinolf Geck about decomposition maps of the generic Iwahori-Hecke algebra H of the symmetric group on n points arising from specialization to characteristic l>0. If the parameter of the algebra is specialized to an element q of GF(l) with multiplicative order e, the conjecture states, that, for el>n, the decomposition map does not depend on l and q, but only on e. The main result of the present work is the following reformulation of the James-Geck conjecture: For el>n every primitive idempotent in the extension of scalars AH is primitive as idempotent in the algebra A'H, where A and A' are rings of characteristic 0 (which are explicitly constructed for l and q), such that A is contained in A' and therefore AH in A'H. Thus an equivalent statement is given, which contains only rings and algebras of characteristic 0. To prove equivalence, generalizations of the well-known methods of lifting of idempotents and of Brauer reciprocity are developed. In addition results and observations are presented, that might lead to an approach to a proof of the above mentioned reformulation. A method is presented, how one can derive explicit formulae for primitive idempotents in non-semi-simple symmetric algebras using matrix representations on projective indecomposable modules. Such matrix representations seem to arise naturally from the Kazhdan-Lusztig cell modules. Another possible attack for a proof stems from another result of the present thesis, an explicit construction of a Wedderburn decomposition for H using the Kazhdan-Lusztig basis.}, cin = {100000}, ddc = {510}, cid = {$I:(DE-82)100000_20140620$}, typ = {PUB:(DE-HGF)11}, urn = {urn:nbn:de:hbz:82-opus-5634}, url = {https://publications.rwth-aachen.de/record/58877}, }