http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
HYPONORMAL SINGULAR INTEGRAL OPERATORS WITH CAUCHY KERNEL ON L<sup>2</sup>
Nakazi, Takahiko Korean Mathematical Society 2018 대한수학회논문집 Vol.33 No.3
For $1{\leq}p{\leq}{\infty}$, let $H^p$ be the usual Hardy space on the unit circle. When ${\alpha}$ and ${\beta}$ are bounded functions, a singular integral operator $S_{{\alpha},{\beta}}$ is defined as the following: $S_{{\alpha},{\beta}}(f+{\bar{g}})={\alpha}f+{\beta}{\bar{g}}(f{\in}H^p,\;g{\in}zH^p)$. When p = 2, we study the hyponormality of $S_{{\alpha},{\beta}}$ when ${\alpha}$ and ${\beta}$ are some special functions.
Range inclusion of two same type concrete operators
Takahiko Nakazi 대한수학회 2016 대한수학회보 Vol.53 No.6
Let $H$ and $K$ be two Hilbert spaces, and let $A$ and $B$ be two bounded linear operators from $H$ to $K$. We are interested in Range$B^\ast \supseteq$ Range$A^\ast $. It is well known that this is equivalent to the inequality $A^\ast A\geq\varepsilon B^\ast B$ for a positive constant $\varepsilon$. We study conditions in terms of symbols when $A$ and $B$ are singular integral operators, Hankel operators or Toeplitz operators, etc.
A Difference of Two Composition Operators on L<sup>2</sup> and H<sup>2</sup>
Nakazi, Takahiko Department of Mathematics 2016 Kyungpook mathematical journal Vol.56 No.1
A finite rank difference of two composition operators is studied on a Hilbert Lebesgue space or a Hilbert Hardy space.
RANGE INCLUSION OF TWO SAME TYPE CONCRETE OPERATORS
Nakazi, Takahiko Korean Mathematical Society 2016 대한수학회보 Vol.53 No.6
Let H and K be two Hilbert spaces, and let A and B be two bounded linear operators from H to K. We are interested in $RangeB^*{\supseteq}RangeA^*$. It is well known that this is equivalent to the inequality $A^*A{\geq}{\varepsilon}B^*B$ for a positive constant ${\varepsilon}$. We study conditions in terms of symbols when A and B are singular integral operators, Hankel operators or Toeplitz operators, etc.
Bounded composition operators from the Bergman space to the Hardy space
Kazuhiro Kasuga,Takahiko Nakazi 대한수학회 2014 대한수학회보 Vol.51 No.4
Letø be an analytic self map of the open unit disc D. In this paper, we study the composition operator Cø from the Bergman space on D to the Hardy space on D.
SPECTRAL AREA ESTIMATES FOR NORMS OF COMMUTATORS
Cho, Muneo,Nakazi, Takahiko Korean Mathematical Society 2007 대한수학회지 Vol.44 No.4
Let A and B be commuting bounded linear operators on a Hilbert space. In this paper, we study spectral area estimates for norms of $A^*B-BA^*$ when A is subnormal or p-hyponormal.
BOUNDED COMPOSITION OPERATORS FROM THE BERGMAN SPACE TO THE HARDY SPACE
Kasuga, Kazuhiro,Nakazi, Takahiko Korean Mathematical Society 2014 대한수학회보 Vol.51 No.4
Let ${\phi}$ be an analytic self map of the open unit disc D. In this paper, we study the composition operator $C_{\phi}$ from the Bergman space on D to the Hardy space on D.