中文

与immaculate tableaux相关的半简单代数

组合数学 2025-07-04 v1

摘要

Given a direct sum AA of full matrix algebras, if there is a combinatorial interpretation associated with both the dimension of AA and the dimensions of the irreducible AA-modules, then this can be thought of as providing an analogue of the famous Frobenius-Young identity n!=λn(fλ)2n! = \sum_{\lambda \vdash n} ( f^{\lambda} )^{2} derived from the semisimple structure of the symmetric group algebra CSn\mathbb{C}S_{n}, letting fλf^{\lambda} denote the number of Young tableaux of partition shape λn\lambda \vdash n. By letting gαg^{\alpha} denote the number of standard immaculate tableaux of composition shape αn\alpha \vDash n, we construct an algebra CIn\mathbb{C}\mathcal{I}_{n} with a semisimple structure such that dimCIn=αn(gα)2\dim \mathbb{C}\mathcal{I}_{n} = \sum_{\alpha \vDash n} (g^{\alpha})^{2} and such that CIn\mathbb{C}\mathcal{I}_{n} contains an isomorphic copy of CSn\mathbb{C}S_{n}. We bijectively prove a recurrence for dimCIn\dim \mathbb{C}\mathcal{I}_{n} so as to construct a basis of CIn\mathbb{C}\mathcal{I}_{n} indexed by permutation-like objects that we refer to as immacutations. We form a basis Bn\mathcal{B}_{n} of CIn\mathbb{C}\mathcal{I}_{n} such that CBn\mathbb{C} \mathcal{B}_n has the structure of a monoid algebra in such a way so that Bn\mathcal{B}_n is closed under the multiplicative operation of CIn\mathbb{C} \mathcal{I}_n, yielding a monoid structure on the set of order-nn immacutations.

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引用

@article{arxiv.2507.02539,
  title  = {Semisimple algebras related to immaculate tableaux},
  author = {John M. Campbell},
  journal= {arXiv preprint arXiv:2507.02539},
  year   = {2025}
}

备注

Submitted for publication