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Combinatorial aspects of representations of groups and algebras

Research Project

Project/Area Number 09640001
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Algebra
Research InstitutionHokkaido University

Principal Investigator

YAMADA Hirofumi  Grad.School of Science, Hokkaido Univ., Asso.Prof., 大学院・理学研究科, 助教授 (40192794)

Co-Investigator(Kenkyū-buntansha) NAKAJIMA Tatsuhiro  Faculty of Economics, Meikai Univ., Lec., 経済学部, 講師 (00286006)
TERAO Hiroaki  Grad.School of Science, Tokyo Metropolitan Univ., Prof., 大学院・理学研究科, 教授 (90119058)
SGIBUKAWA Youichi  Grad.School of Science, Hokkaido Univ., Inst., 大学院・理学研究科, 助手 (90241299)
SAITO Mutsumi  Grad.School of Science, Hokkaido Univ., Asso.Prof., 大学院・理学研究科, 助教授 (70215565)
YAMASHITA Hiroshi  Grad.School of Science, Hokkaido Univ., Asso.Prof., 大学院・理学研究科, 助教授 (30192793)
Project Period (FY) 1997 – 1998
Project Status Completed (Fiscal Year 1998)
Budget Amount *help
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1998: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1997: ¥1,400,000 (Direct Cost: ¥1,400,000)
Keywordsaffine Lie algebras / Schur functions / decomposition matrices / complex reflection groups / シューア函教 / ウエイトベクトル
Research Abstract

I focused on a relationship of Schur's Q-functions and affine Lie algebras. First I found that the Q-functions, expressed as polynomials of power sum symmetric functions, form a weight basis for the basic representation of certain affine Lie algebras, realized on a polynomial ring. Q-functions are parametrized by the strict partitions. Using some combinatorics of Young diagrams, I determined the weight of the given Q-function. This procedure was applied to the simplest affine lie algebra $A^{(1)}_1$ to find an identity satisfied by Schur functions and Q-functions indexed by some specific partitions. At first this identity seemed funny : However this was proved to be true by making use of decomposition matrices of the spin representations of the symmetric group. By virtue of this fact, I turned to a study of the decomposition matrices themselves. As a first result I proved that the determinant of the decomposition matrix of the spin representations is equal to a power of two when the characteristic equals two.
Another feature of my research is the so called "higher Specht polynomials" for the complex reflection group G(r, p, n). The group G(r, p, n) acts on the polynomial ring of n variables. The "coinvariant ring" is the quotient by the ideal which is generated by invariants over the group. It is known that the action of G(r, p, n) on this coinvariant ring is isomorphic to the regular representation. The higher Specht polynomials appear naturally as basis vectors of each irreducible component.

Report

(3 results)
  • 1998 Annual Research Report   Final Research Report Summary
  • 1997 Annual Research Report
  • Research Products

    (8 results)

All Other

All Publications (8 results)

  • [Publications] S.Ariki et al.: "Reduced Sclur junctions and Littlewood-Richardson coefficients" Journal of London Mathematical Society. in press.

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] H.Morita et.al.: "Higher Specht polynamials for the complex reflcetion group G (r, p, n)" Hokkaido Mathematical Journal. 27. 505-515 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] S.Ariki, T.Nakajima and H.-F.Yamada: "Reduced Schur functions and Littlewood-Richardson coefficients" Journal of London Mathematical Society. in press.

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] H.Morita and H.-F.Yamada: "Higher Specht polynomials for the complex reflection group G (r, p, n)" Hokkaido Mathematical Journal. 27. 505-515 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] S.Ariki et al.: "Reduced schur funotions and Littlewood-Richardeon coefficients" Jounal of London Mathematical Society. (in press).

    • Related Report
      1998 Annual Research Report
  • [Publications] T.Nakajima: "On reduced Q-functions" Hiroshima Mathematical Journal. 27-3. 407-414 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] H.Morita: "Higher Specht polynomials for complex reflection group G (r.p.n)" Hokkaido Mathematical Journal. (in press).

    • Related Report
      1997 Annual Research Report
  • [Publications] T.Nakajima: "Sclur's Q-functions and affine hie algelras of type D^<(2)>_<e+1>" Proceedings 10^<th> International Conforence on FPSAC. (in press).

    • Related Report
      1997 Annual Research Report

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Published: 1997-04-01   Modified: 2016-04-21  

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