English

Infinite and finite dimensional Hilbert tensors

Spectral Theory 2014-01-22 v2

Abstract

For an mm-order nn-dimensional Hilbert tensor (hypermatrix) Hn=(Hi1i2im)\mathcal{H}_n=(\mathcal{H}_{i_1i_2\cdots i_m}), Hi1i2im=1i1+i2++imm+1, i1,,im=1,2,,n\mathcal{H}_{i_1i_2\cdots i_m}=\frac1{i_1+i_2+\cdots+i_m-m+1},\ i_1,\cdots, i_m=1,2,\cdots,n its spectral radius is not larger than nm1sinπnn^{m-1}\sin\frac{\pi}{n}, and an upper bound of its EE-spectral radius is nm2sinπnn^{\frac{m}2}\sin\frac{\pi}{n}. Moreover, its spectral radius is strictly increasing and its EE-spectral radius is nondecreasing with respect to the dimension nn. When the order is even, both infinite and finite dimensional Hilbert tensors are positive definite. We also show that the mm-order infinite dimensional Hilbert tensor (hypermatrix) H=(Hi1i2im)\mathcal{H}_\infty=(\mathcal{H}_{i_1i_2\cdots i_m}) defines a bounded and positively (m1)(m-1)-homogeneous operator from l1l^1 into lpl^p (1<p<1<p<\infty), and the norm of corresponding positively homogeneous operator is smaller than or equal to π6\frac{\pi}{\sqrt6}.

Keywords

Cite

@article{arxiv.1401.4966,
  title  = {Infinite and finite dimensional Hilbert tensors},
  author = {Yisheng Song and Liqun Qi},
  journal= {arXiv preprint arXiv:1401.4966},
  year   = {2014}
}