Classify all blocks of the centraliser algebra of symmetric groups

Classify the p-blocks of the centraliser algebra kS_m^{S_l} by proving that two Specht modules S^{\mu_1\setminus\lambda_1} and S^{\mu_2\setminus\lambda_2}, for skew-partitions of sizes l and m, lie in the same p-block if and only if core_p(\mu_1)=core_p(\mu_2) and core_p(\lambda_1)=core_p(\lambda_2).

Background

The centraliser algebra kS_m{S_l} is the principal object of the paper, and its modular block structure is described by a conjecture attributed to Ellers and Murray. The conjecture predicts that the block of a skew Specht module is determined independently by the p-cores of its outer and inner partitions. The paper proves this prediction for generalised ribbon blocks and belt blocks, but leaves the classification for arbitrary blocks unresolved.

References

Our main conjecture (which is implicit in the work of Ellers and Murray ) predicts that the case of the centraliser algebra works in the same way.

Ribbon blocks for centraliser algebras of symmetric groups  (2502.13867 - Fayers et al., 19 Feb 2025) in Section 2.5, "Combinatorial blocks"