Dual Equivalence Graphs Revisited
In 2007 Sami Assaf introduced dual equivalence graphs as a method for demonstrating that a quasisymmetric function is Schur positive. The method involves the creation of a graph whose vertices are weighted by Ira Gessel's fundamental quasisymmetric functions so that the sum of the weights of a...
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| Format: | Article |
| Language: | English |
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Discrete Mathematics & Theoretical Computer Science
2013-01-01
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| Series: | Discrete Mathematics & Theoretical Computer Science |
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| Online Access: | https://dmtcs.episciences.org/2354/pdf |
| _version_ | 1797270310321389568 |
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| author | Austin Roberts |
| author_facet | Austin Roberts |
| author_sort | Austin Roberts |
| collection | DOAJ |
| description | In 2007 Sami Assaf introduced dual equivalence graphs as a method for demonstrating that a quasisymmetric function is Schur positive. The method involves the creation of a graph whose vertices are weighted by Ira Gessel's fundamental quasisymmetric functions so that the sum of the weights of a connected component is a single Schur function. In this paper, we improve on Assaf's axiomatization of such graphs, giving locally testable criteria that are more easily verified by computers. We then demonstrate the utility of this result by giving explicit Schur expansions for a family of Lascoux-Leclerc-Thibon polynomials. This family properly contains the previously known case of polynomials indexed by two skew shapes, as was described in a 1995 paper by Christophe Carré and Bernard Leclerc. As an immediate corollary, we gain an explicit Schur expansion for a family of modified Macdonald polynomials in terms of Yamanouchi words. This family includes all polynomials indexed by shapes with less than four cells in the first row and strictly less than three cells in the second row, a slight improvement over the known two column case described in 2005 by James Haglund, Mark Haiman, and Nick Loehr. |
| first_indexed | 2024-04-25T02:02:14Z |
| format | Article |
| id | doaj.art-cf3a0d0c12a145a58d520a0aadbf0027 |
| institution | Directory Open Access Journal |
| issn | 1365-8050 |
| language | English |
| last_indexed | 2024-04-25T02:02:14Z |
| publishDate | 2013-01-01 |
| publisher | Discrete Mathematics & Theoretical Computer Science |
| record_format | Article |
| series | Discrete Mathematics & Theoretical Computer Science |
| spelling | doaj.art-cf3a0d0c12a145a58d520a0aadbf00272024-03-07T14:52:36ZengDiscrete Mathematics & Theoretical Computer ScienceDiscrete Mathematics & Theoretical Computer Science1365-80502013-01-01DMTCS Proceedings vol. AS,...Proceedings10.46298/dmtcs.23542354Dual Equivalence Graphs RevisitedAustin Roberts0Department of Mathematics [Seattle]In 2007 Sami Assaf introduced dual equivalence graphs as a method for demonstrating that a quasisymmetric function is Schur positive. The method involves the creation of a graph whose vertices are weighted by Ira Gessel's fundamental quasisymmetric functions so that the sum of the weights of a connected component is a single Schur function. In this paper, we improve on Assaf's axiomatization of such graphs, giving locally testable criteria that are more easily verified by computers. We then demonstrate the utility of this result by giving explicit Schur expansions for a family of Lascoux-Leclerc-Thibon polynomials. This family properly contains the previously known case of polynomials indexed by two skew shapes, as was described in a 1995 paper by Christophe Carré and Bernard Leclerc. As an immediate corollary, we gain an explicit Schur expansion for a family of modified Macdonald polynomials in terms of Yamanouchi words. This family includes all polynomials indexed by shapes with less than four cells in the first row and strictly less than three cells in the second row, a slight improvement over the known two column case described in 2005 by James Haglund, Mark Haiman, and Nick Loehr.https://dmtcs.episciences.org/2354/pdfdual equivalence graphllt polynomialmacdonald polynomialschur expansionquasisymmetric function[info.info-dm] computer science [cs]/discrete mathematics [cs.dm] |
| spellingShingle | Austin Roberts Dual Equivalence Graphs Revisited Discrete Mathematics & Theoretical Computer Science dual equivalence graph llt polynomial macdonald polynomial schur expansion quasisymmetric function [info.info-dm] computer science [cs]/discrete mathematics [cs.dm] |
| title | Dual Equivalence Graphs Revisited |
| title_full | Dual Equivalence Graphs Revisited |
| title_fullStr | Dual Equivalence Graphs Revisited |
| title_full_unstemmed | Dual Equivalence Graphs Revisited |
| title_short | Dual Equivalence Graphs Revisited |
| title_sort | dual equivalence graphs revisited |
| topic | dual equivalence graph llt polynomial macdonald polynomial schur expansion quasisymmetric function [info.info-dm] computer science [cs]/discrete mathematics [cs.dm] |
| url | https://dmtcs.episciences.org/2354/pdf |
| work_keys_str_mv | AT austinroberts dualequivalencegraphsrevisited |