19,284 research outputs found
The necessary and sufficient conditions of copositive tensors
In this paper, it is proved that (strict) copositivity of a symmetric tensor
is equivalent to the fact that every principal sub-tensor of
has no a (non-positive) negative -eigenvalue. The
necessary and sufficient conditions are also given in terms of the
-eigenvalue of the principal sub-tensor of the given tensor. This
presents a method of testing (strict) copositivity of a symmetric tensor by
means of the lower dimensional tensors. Also the equivalent definition of
strictly copositive tensors is given on entire space .Comment: 13 pages. arXiv admin note: text overlap with arXiv:1302.608
Tensor Complementarity Problem and Semi-positive Tensors
The tensor complementarity problem (\q, \mathcal{A}) is to
\mbox{ find } \x \in \mathbb{R}^n\mbox{ such that }\x \geq \0, \q +
\mathcal{A}\x^{m-1} \geq \0, \mbox{ and }\x^\top (\q + \mathcal{A}\x^{m-1}) =
0. We prove that a real tensor is a (strictly) semi-positive
tensor if and only if the tensor complementarity problem (\q, \mathcal{A})
has a unique solution for \q>\0 (\q\geq\0), and a symmetric real tensor is
a (strictly) semi-positive tensor if and only if it is (strictly) copositive.
That is, for a strictly copositive symmetric tensor , the tensor
complementarity problem (\q, \mathcal{A}) has a solution for all \q \in
\mathbb{R}^n
Infinite and finite dimensional Hilbert tensors
For an -order dimensional Hilbert tensor (hypermatrix)
, its
spectral radius is not larger than , and an upper
bound of its -spectral radius is . Moreover,
its spectral radius is strictly increasing and its -spectral radius is
nondecreasing with respect to the dimension . When the order is even, both
infinite and finite dimensional Hilbert tensors are positive definite. We also
show that the -order infinite dimensional Hilbert tensor (hypermatrix)
defines a bounded and
positively -homogeneous operator from into (),
and the norm of corresponding positively homogeneous operator is smaller than
or equal to
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