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Specht modules decompose as alternating sums of restrictions of Schur modules.
- Source :
- Proceedings of the American Mathematical Society; Mar2020, Vol. 148 Issue 3, p1015-1029, 15p
- Publication Year :
- 2020
-
Abstract
- Schur modules give the irreducible polynomial representations of the general linear group GL<subscript>t</subscript>. Viewing the symmetric group S<subscript>t</subscript>as a subgroup of GL<subscript>t</subscript>, we may restrict Schur modules to S<subscript>t</subscript> and decompose the result into a direct sum of Specht modules, the irreducible representations of S<subscript>t</subscript>. We give an equivariant Möbius inversion formula that we use to invert this expansion in the representation ring for S<subscript>t</subscript> for t large. In addition to explicit formulas in terms of plethysms, we show the coefficients that appear alternate in sign by degree. In particular, this allows us to define a new basis of symmetric functions whose structure constants are stable Kronecker coefficients and which expand with signs alternating by degree into the Schur basis. [ABSTRACT FROM AUTHOR]
- Subjects :
- IRREDUCIBLE polynomials
SYMMETRIC functions
POLYNOMIAL rings
Subjects
Details
- Language :
- English
- ISSN :
- 00029939
- Volume :
- 148
- Issue :
- 3
- Database :
- Complementary Index
- Journal :
- Proceedings of the American Mathematical Society
- Publication Type :
- Academic Journal
- Accession number :
- 141437881
- Full Text :
- https://doi.org/10.1090/proc/14815