Hwa-Long Gau

activity

20092026

most citedWeighted Shift Matrices: Unitary Equivalence, Reducibility and Numerical Ranges

23 citations · 64 across the 9 of their papers we have counts for

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Showing 2012Show all

2 papers · 1 filter

math.FA2012★ 15 cited

Higher-rank Numerical Ranges and Kippenhahn Polynomials

Hwa-Long Gau, Pei Yuan Wu

We prove that two n-by-n matrices A and B have their rank-k numerical ranges $Λ_{k} (A)$ and $Λ_{k} (B)$ equal to each other for all k, $1 \leq k \leq ⌊ n /2 ⌋ + 1$ , if and only if t…

math.FA2012★ 23 cited

Weighted Shift Matrices: Unitary Equivalence, Reducibility and Numerical Ranges

Hwa-Long Gau, Ming-Cheng Tsai, Han-Chun Wang

An $n$ -by- $n$ ( $n \geq 3$ ) weighted shift matrix $A$ is one of the form $$[{array}{cccc}0 & a_1 & & & 0 & \ddots & & & \ddots & a_{n-1} a_n & & & 0{array}],$$ where the $a_{j}$ 's, call…