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The Goldman-Rota identity and the Grassmann scheme. (English) Zbl 1300.05324

Summary: We inductively construct an explicit (common) orthogonal eigenbasis for the elements of the Bose-Mesner algebra of the Grassmann scheme.{ }The key step is a constructive, linear algebraic interpretation of the Goldman-Rota recurrence for the number of subspaces of a finite vector space. This interpretation shows that the up operator on subspaces has an explicitly given recursive structure. { }Using the interpretation above we inductively construct an explicit orthogonal symmetric Jordan basis with respect to the up operator and write down the singular values, i.e., the ratio of the lengths of the successive vectors in the Jordan chains. The collection of all vectors in this basis of a fixed rank \(m\) forms a (common) orthogonal eigenbasis for the elements of the Bose-Mesner algebra of the Grassmann scheme of \(m\)-dimensional subspaces. We also pose a bijective proof problem on the spanning trees of the Grassmann graphs.

MSC:

05E15 Combinatorial aspects of groups and algebras (MSC2010)
05E30 Association schemes, strongly regular graphs

References:

[1] C. Bachoc, F. Vallentin and A. Passuello, Bounds for projective codes from semidefinite programming, Advances in Math. of Communications, 7:127-145 (2013). · Zbl 1317.94164
[2] F. Bergeron, Feedback by Francois Bergeron to the paper “binomial(5,2) proofs that binomial(n, k) 6 binomial(n, k + 1) if k < n/2”, by D. Zeilberger, Personal journal of Shalosh B. Ekhad and Doron Zeilberger, available athttp://www.math.rutgers. edu/ zeilberg/mamarim/mamarimhtml/trivialFB.html
[3] O. Bernardi,On the spanning trees of the hypercube and other products of graphs, Electronic J. Comb., 19(4):#P51 (2012). · Zbl 1267.05020
[4] A. E. Brouwer, and W. H. Haemers, Spectra of graphs, Springer, 2012. · Zbl 1231.05001
[5] T. Ceccherini-Silberstein, F. Scarabotti, and F. Tolli, Harmonic analysis on finite groups, Cambridge University Press, 2008. · Zbl 1149.43001
[6] P. Delsarte, Association schemes and t-designs in regular semilattices, J. Combinatorial Theory, Series A, 20:230-243 (1976). · Zbl 0342.05020
[7] P. Delsarte, Hahn polynomials, discrete harmonics, and t-designs, SIAM J. Applied Math., 34:157-166 (1978). · Zbl 0533.05009
[8] C. F. Dunkl, An addition theorem for some q-Hahn polynomials, Monatsh. Math., 85:5-37 (1978). · Zbl 0345.33010
[9] K. Engel, Sperner theory, Cambridge University Press, 1997. · Zbl 0868.05001
[10] J. Goldman and G. -C. Rota, The number of subspaces of a vector space, in Recent progress in Combinatorics (Proc. Third Waterloo Conf. on Combinatorics 1968), Academic Press:75-83 (1969). · Zbl 0196.02801
[11] R. L Graham, S. Y. R. Li and W. W. Li,On the structure of t-designs, SIAM J. Alg. Discr. Methods, 1:8-14 (1980). the electronic journal of combinatorics 21(1) (2014), #P1.3722 · Zbl 0499.05012
[12] J. E. Graver and W. B. Jurkat, The module structure of integral designs, J. Comb. Theory, Ser. A, 15:75-90 (1973). · Zbl 0259.05020
[13] J. R. Griggs, Sufficient conditions for a symmetric chain order, SIAM J. Applied Math., 32:807-809 (1977). · Zbl 0359.06004
[14] S. Hitzemann and W. Hochst¨attler, On the combinatorics of Galois numbers, Discrete Math., 310:3551-3557 (2010). · Zbl 1226.11030
[15] G. James, and M.Liebeck, Representations and Characters of Groups, Cambridge University Press, 2001. · Zbl 0981.20004
[16] A. Joyal, Une th´eorie combinatoire des s´eries formelles, Advances in Math., 42:1-82 (1981). · Zbl 0491.05007
[17] V. Kac and P. Cheung, Quantum Calculus, Springer-Verlag, 2002. · Zbl 0986.05001
[18] D. E. Knuth, Combinatorial Matrices, in Selected papers on discrete mathematics, CSLI lecture Notes, 106, CSLI Publications, Stanford, CA:177-186 (2003). · Zbl 1052.01015
[19] J. M. Marco and J. Parcet,On the natural representation of S(Ω) into L2(P(Ω)): discrete harmonics and Fourier transform, J. Comb. Theory, Ser. A, 100:153-175 (2002). · Zbl 1013.05090
[20] J. M. Marco and J. Parcet, Laplacian operators and Radon transforms on Grassmann graphs, Monatsh. Math., 150:97-132 (2007). · Zbl 1113.33019
[21] A. Nijenhuis, A. E. Solow and H. S. Wilf, Bijective methods in the theory of finite vector spaces, J. Comb. Theory, Ser. A, 37:80-84 (1984). · Zbl 0541.05003
[22] R. A. Proctor, Representations of sl(2, C) on posets and the Sperner property, SIAM J. Alg. Discr. Methods, 3:275-280 (1982). · Zbl 0496.06004
[23] A. Schrijver, New code upper bounds from the Terwilliger algebra and semidefinite programming, IEEE Tran. Information Theory, 51:2859-2866 (2005). · Zbl 1298.94152
[24] N. Singhi, Tags on subsets, Discrete Math., 306:1610-1623 (2006). · Zbl 1095.05004
[25] M. K. Srinivasan, Symmetric chains, Gelfand-Tsetlin chains, and the Terwilliger algebra of the binary Hamming scheme, J. Algebraic Comb., 34:301-322 (2011). · Zbl 1229.05298
[26] M. K. Srinivasan, A positive combinatorial formula for the complexity of the q-analog of the n-cube, Electronic J. Comb., 19(2):#P34 (2012). · Zbl 1244.05019
[27] M. K. Srinivasan, Notes on explicit block diagonalization, in Combinatorial Matrix Theory and Generalized Inverses of Matrices, Springer:13-31 (2013). · Zbl 1286.06020
[28] R. P. Stanley, Variations on differential posets, in Invariant Theory and Tableaux, volume 19 of IMA Vol. Math. Appl., Springer:145-165 (1990). · Zbl 0707.06001
[29] R. P. Stanley, Enumerative Combinatorics - Volume 1, Second Edition, Cambridge University Press, 2012. · Zbl 1247.05003
[30] P. Terwilliger, The incidence algebra of a uniform poset, in Coding theory and design theory, Part I, volume 20 of IMA Vol. Math. Appl., Springer:193-212 (1990). · Zbl 0737.05032
[31] F. Vogt and B. Voigt, Symmetric chain decompositions of linear lattices, Comb., Prob. and Comp., 6:231-245 (1997). · Zbl 0882.06003
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