**Speaker:** Maria Chlouveraki (Athens)

**Title:** *Defects and Weights of Blocks*

**Abstract:**

The irreducible representations of the Ariki-Koike algebra are labelled by multipartitions. To each multipartition we can attach a numerical datum, its defect, which measures the complexity of the corresponding block of the Ariki-Koike algebra. In a joint work with Nicolas Jacon we proved that the defect is equal to the weight of the multipartition, a well-known block invariant defined by Fayers in 2006. In this talk, our proof, which uses the combinatorics of the abaci, will be presented.