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A138540 Moment sequence of tr(A) in USp(6). 7
1, 0, 1, 0, 3, 0, 15, 0, 104, 0, 909, 0, 9449, 0, 112398, 0, 1489410, 0, 21562086, 0, 336086022, 0, 5577242292, 0, 97671172836, 0, 1792348213025, 0, 34268124834495, 0, 679376016769260, 0, 13911118850603610, 0, 293220749128031010, 0 (list; graph; refs; listen; history; internal format)
OFFSET

0,5

COMMENTS

If A is a random matrix in the compact group USp(6) (6x6 complex matrices which are unitary and symplectic), then a(n)=E[(tr(A))^n] is the n-th moment of the trace of A.

The multiplicity of the trivial representation in the n-th tensor power of the standard representation of USp(6).

Number of returning walks of length n on a cubic lattice remaining in the chamber x >= y >= z >= 0.

Under a generalized Sato-Tate conjecture, this is the moment sequence of the distribution of unitarized Frobenius traces a_p/sqrt(p) (as p varies), for almost all genus 3 curves.

REFERENCES

Kiran S. Kedlaya and Andrew V. Sutherland, "Hyperelliptic curves, L-polynomials and random matrices", preprint, 2008.

David J. Grabiner and Peter Magyar, "Random walks in Weyl chambers and the decomposition of tensor powers", Journal of Algebraic Combinatorics, vol. 2 (1993), no. 3, pp 239-260.

Nicholas M. Katz and Peter Sarnak, "Random Matrices, Frobenius Eigenvalues and Monodromy", AMS, 1999.

LINKS

Kiran S. Kedlaya and Andrew V. Sutherland, Hyperelliptic curves, L-polynomials and random matrices.

FORMULA

mgf is A(z) = det[F_{i+j-2}(z)], 1<=i,j<=g, where F_m(z) = Sum_j Binom(m,j)(I_{2j-m}(2z)-I_{2j-m+2}) and I_k(z) is the hyperbolic Bessel function (of the first kind) of order k.

mgf: A(z) = det[F_{i+j-2}(z)], 1<=i,j<=3, where F_m(z) = Sum_j Binom(m,j)(I_{2j-m}(2z)-I_{2j-m+2}(2z)) and I_k(z) is the hyperbolic Bessel function (of the first kind) of order k.

EXAMPLE

a(4)=3 because E[(tr(A)^4] = 3 for a random matrix A in USp(6).

CROSSREFS

Cf. 138349.

Sequence in context: A135399 A065121 A167339 * A123023 A130637 A054882

Adjacent sequences:  A138537 A138538 A138539 * A138541 A138542 A138543

KEYWORD

nonn

AUTHOR

Andrew V. Sutherland (drew(AT)math.mit.edu), Mar 24 2008, Apr 01 2008

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Last modified February 13 17:56 EST 2012. Contains 205526 sequences.