Decomposition of spin representations of symmetric groups in characteristic 2

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• Lucia Morotti (Hannover University)
• Tuesday 16 November 2021, 15:00-16:00
• https://bham-ac-uk.zoom.us/j/88435218897?pwd=Y0d0Ukg2aW1hZ3hZUE16RTBaSlFOZz09.

If you have a question about this talk, please contact Gareth Tracey.

Any representation of a double cover of a symmetric group $\widetilde{S}_n$ can also be viewed as a representation of $S_n$ when reduced to characteristic 2. However not much is known about the corresponding decomposition matrices. For example, while decomposition numbers of Specht modules indexed by 2-parts partitions are known, the decomposition numbers of spin irreducible modules indexed by 2-parts partitions are still mostly unknown, with in most cases only multiplicities of maximal composition factors (under a certain ordering of the modular irreducible representations) being known.

In this talk I will characterise irreducible representations that appear when reducing 2-parts spin representations to characteristic 2 and describe part of the corresponding rows of the decomposition matrices.

This talk is part of the Algebra seminar series.

This talk is included in these lists:

• Algebra seminar
• School of Mathematics events
• https://bham-ac-uk.zoom.us/j/88435218897?pwd=Y0d0Ukg2aW1hZ3hZUE16RTBaSlFOZz09

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