Some positive differences of products of Schur functions

dc.creatorBergeron, Francois
dc.creatorMcNamara, Peter
dc.date2004-12-14
dc.date.accessioned2026-07-07T05:15:18Z
dc.date.available2026-07-07T05:15:18Z
dc.descriptionThe product $s_μs_ν$ of two Schur functions is one of the most famous examples of a Schur-positive function, i.e. a symmetric function which, when written as a linear combination of Schur functions, has all positive coefficients. We ask when expressions of the form $s_λs_ρ- s_μs_ν$ are Schur-positive. This general question seems to be a difficult one, but a conjecture of Fomin, Fulton, Li and Poon says that it is the case at least when $λ$ and $ρ$ are obtained from $μ$ and $ν$ by redistributing the parts of $μ$ and $ν$ in a specific, yet natural, way. We show that their conjecture is true in several significant cases. We also formulate a skew-shape extension of their conjecture, and prove several results which serve as evidence in favor of this extension. Finally, we take a more global view by studying two classes of partially ordered sets suggested by these questions.
dc.description24 pages, 5 PostScript figures, multiple other figures use LaTeX picture environment
dc.identifierhttps://arxiv.org/abs/math/0412289
dc.identifierhttp://arxiv.org/abs/math/0412289
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/73585
dc.subjectCombinatorics
dc.subject05E05 (Primary) 05E10 (Secondary)
dc.titleSome positive differences of products of Schur functions
dc.typetext

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