Noncommutative symmetric functions VI: Free quasi-symmetric functions and related algebras
arXiv:math/0105065
Abstract
This article is devoted to the study of several algebras which are related to symmetric functions, and which admit linear bases labelled by various combinatorial objects: permutations (free quasi-symmetric functions), standard Young tableaux (free symmetric functions) and packed integer matrices (matrix quasi-symmetric functions). Free quasi-symmetric functions provide a kind of noncommutative Frobenius characteristic for a certain category of modules over the 0-Hecke algebras. New examples of indecomposable -modules are discussed, and the homological properties of are computed for small . Finally, the algebra of matrix quasi-symmetric functions is interpreted as a convolution algebra.
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