Department of Mathematics
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Rings and Modules Seminar
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R. Padmanabhan
padman@cc.umanitoba.ca
Department of Mathematics
University of Manitoba
Thursday September 28, 2006
Abstract:
It was shown by H. Schröter [Nachr. Ges. Wiss. Göttingen 1889, 193--236] that one combinatorially possible (10,3) design cannot be realized in a projective plane over any field. In 1954, R. Lauffer [Math. Nachrichten, vol. 11] gave a representation of this design over the infinite division ring of quaternions. This proves that the design, viewed as a ternary implicational system, is strictly consistent, meaning that it is impossible to derive x=y from the ten defining relations. Here we give an elementary algebraic proof of Schröter's theorem. We also give a group representation of rank 3 for this configuration and show that 3 is the minimal possible such representation. This is part of an unpublished set of notes on group representations written in collaboration with Late Professor Mendelsohn and Barry Wolk. |