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The decomposition of the permutation character \(1^{\text{GL}(2n,q)}_{\text{GL}(n,q^2)}\). (English) Zbl 1031.20040

Let \(p\) be a prime and let \(q=p^a\), where \(a\) is a positive integer. Let \(\text{GL}_n(q)\) denote the general linear group of degree \(n\) over the field of \(q\) elements. The group \(H=\text{GL}_n(q^2)\) is a subgroup of \(G=\text{GL}_{2n}(q)\). N. F. J. Inglis, M. W. Liebeck and J. Saxl proved [in Math. Z. 192, 329-337 (1986; Zbl 0578.20006)] that the permutation character \(\pi\) of \(G\) acting on the cosets of \(H\) is multiplicity-free, meaning that each irreducible constituent of \(\pi\) has multiplicity one. This follows since each double coset \(HxH\) of \(H\) in \(G\) is equal to its inverse coset \(Hx^{-1}H\). The authors of the present paper identify the irreducible constituents of \(\pi\), using Green’s parametrization of the irreducible characters of \(G\). They show also that the number of irreducible constituents of \(\pi\) is \(\sum q^{l(\lambda)}\), the sum extending over all partitions \(\lambda\) of \(n\), where \(l(\lambda)\) equals the number of parts of \(\lambda\). The authors also note that A. Henderson has obtained their main theorem when \(q\) is odd [J. Algebra 261, No. 1, 102-144 (2003; Zbl 1020.20030)].

MSC:

20G05 Representation theory for linear algebraic groups
20G40 Linear algebraic groups over finite fields
20C33 Representations of finite groups of Lie type
Full Text: DOI

References:

[1] Bannai, E., Character tables of commutative association schemes, (Kantor, W. M.; etal., Finite Geometries, Buildings, and Related Topics (1990), Clarendon Press: Clarendon Press Oxford), 105-128 · Zbl 0757.05100
[2] Bannai, E.; Hao, S.; Song, S.-Y., Character tables of the association schemes of finite orthogonal groups acting on the nonisotropic points, J. Combin. Theory Ser. A, 54, 164-200 (1990) · Zbl 0762.20005
[3] Bannai, E.; Hao, S.; Song, S.-Y.; Wei, H., Character tables of certain association schemes coming from finite unitary and symplectic groups, J. Algebra, 144, 189-213 (1991) · Zbl 0824.20009
[4] Bannai, E.; Ito, T., Algebraic Combinatorics I (1984), Benjamin/Cummings: Benjamin/Cummings Menlo Park, CA · Zbl 0555.05019
[5] Bannai, E.; Kawanaka, N.; Song, S.-Y., The character table of the Hecke algebra \(H(GL2n(Fq),Sp2n(Fq))\), J. Algebra, 129, 320-366 (1990) · Zbl 0761.20013
[6] Carlitz, L., Some theorems on irreducible reciprocal polynomials over a finite field, J. Reine Angew. Math., 227, 212-220 (1967) · Zbl 0155.09801
[7] Curtis, C. W.; Reiner, I., Methods of Representation Theory (1990), Wiley: Wiley New York, Vol. I · Zbl 0698.20001
[8] Gow, R., Two multiplicity-free permutation representations of the general linear group \(GL (n,q^2)\), Math. Z., 188, 45-54 (1984) · Zbl 0546.20035
[9] Green, J. A., The characters of the finite general linear groups, Trans. Amer. Math. Soc., 80, 402-447 (1955) · Zbl 0068.25605
[10] Henderson, A., Spherical functions of the symmetric space \(G(Fq^2)/G(Fq)\), Represent. Theory, 5, 581-614 (2001) · Zbl 0986.20042
[11] Henderson, A., Symmetric subgroup invariants in irreducible representations of \(G(Fq)\), when \(G= GL_n \), J. Algebra, 261, 102-144 (2003) · Zbl 1020.20030
[12] N.F.J. Inglis, Multiplicity-free permutation characters, distance-transitive graphs and classical groups, PhD thesis, Cambridge, 1988; N.F.J. Inglis, Multiplicity-free permutation characters, distance-transitive graphs and classical groups, PhD thesis, Cambridge, 1988
[13] Inglis, N. F.J.; Liebeck, M. W.; Saxl, J., Multiplicity-free permutation representations of finite linear groups, Math. Z., 192, 329-337 (1986) · Zbl 0578.20006
[14] Inglis, N. F.J.; Saxl, J., An explicit model for the complex representations of the finite general linear groups, Arch. Math. (Basel), 57, 424-431 (1991) · Zbl 0826.20038
[15] Kawanaka, N., On subfield symmetric spaces over a finite field, Osaka J. Math., 28, 759-791 (1991) · Zbl 0789.20040
[16] Klyachko, A. A., Models for the complex representations of the groups \(GL (n,q)\), Math. USSR-Sb., 48, 365-379 (1984) · Zbl 0543.20026
[17] Lawther, R., The action of \(F_4(q)\) on cosets of \(B_4(q)\), J. Algebra, 212, 79-118 (1999) · Zbl 0923.20010
[18] Lusztig, G., Symmetric spaces over a finite field, (Cartier, P.; etal., The Grothendieck Festschrift, Vol. III. The Grothendieck Festschrift, Vol. III, Progr. Math., 88 (1990), Birkhäuser: Birkhäuser Boston, MA), 57-81 · Zbl 0773.20012
[19] Macdonald, I. G., Symmetric Functions and Hall Polynomials, Oxford Math. Monogr. (1995), Oxford University Press · Zbl 0487.20007
[20] Saxl, J., On multiplicity-free permutation representations, (Cameron, P. J.; etal., Finite Geometries and Designs. Finite Geometries and Designs, London Math. Soc. Lecture Note Ser., 49 (1981), Cambridge University Press: Cambridge University Press Cambridge), 337-353 · Zbl 0578.20006
[21] Springer, T. A.; Zelevinsky, A. V., Characters of \(GL(n,Fq)\) and Hopf algebras, J. London Math. Soc. (2), 30, 27-43 (1984) · Zbl 0551.20022
[22] Tanaka, H., Some results on the multiplicity-free permutation group \(GL (4,q)\) acting on \(GL (4,q)/ GL (2,q^2)\), (Codes, Lattices, Vertex Operator Algebras and Finite Groups (2001), Research Institute for Mathematical Sciences: Research Institute for Mathematical Sciences Kyoto University), 127-139, in Japanese · Zbl 0991.20507
[23] Terras, A., Fourier Analysis on Finite Groups and Applications. Fourier Analysis on Finite Groups and Applications, London Math. Soc. Student Texts, 43 (1999), Cambridge University Press: Cambridge University Press Cambridge · Zbl 0928.43001
[24] Thoma, E., Die Einschränkung der Charaktere von \(GL (n,q)\) auf \(GL (n\)−\(1,q)\), Math. Z., 119, 321-338 (1971) · Zbl 0205.32602
[25] Zelevinsky, A. V., Representations of Finite Classical Groups: A Hopf Algebra Approach. Representations of Finite Classical Groups: A Hopf Algebra Approach, Lecture Notes in Math., 869 (1981), Springer-Verlag: Springer-Verlag Berlin · Zbl 0465.20009
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