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arXiv · 1305.5947

Dimensions of Ext-groups of Weyl modules for GL_2

Stephan Baier·Sergey Lamzin·Vanessa Miemietz
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Abstract

Let F be an algebraically closed field of positive characteristic p. The third author and Will Turner gave an explicit description of the extension algebra of Weyl modules for GL_2(F). This, in particular, produced an explicit basis. We examine this basis and use it to give upper and lower bounds for the growth behaviour of the dimensions of Ext-groups. Moreover, we implement an algorithm to determine the dimension of any given Ext-group.

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Stephan Baier, Sergey Lamzin, Vanessa Miemietz. 2013-05-31. Dimensions of Ext-groups of Weyl modules for GL_2. https://arxiv.org/abs/1305.5947

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