• 제목/요약/키워드: F-space

검색결과 1,796건 처리시간 0.031초

Gf-SPACES FOR MAPS AND POSTNIKOV SYSTEMS

  • Yoon, Yeon Soo
    • 충청수학회지
    • /
    • 제22권4호
    • /
    • pp.831-841
    • /
    • 2009
  • For a map f : A $\rightarrow$ X, we define and study a concept of $G^f$-space for a map, which is a generalized one of a G-space. Any G-space is a $G^f$-space, but the converse does not hold. In fact, $S^2$ is a $G^{\eta}$-space, but not G-space. We show that X is a $G^f$-space if and only if $G_n$(A, f,X) = $\pi_n(X)$ for all n. It is clear that any $H^f$-space is a $G^f$-space and any $G^f$-space is a $W^f$-space. We can also obtain some results about $G^f$-spaces in Postnikov systems for spaces, which are generalization of Haslam's results about G-spaces.

  • PDF

COCOMPACT F-BASES AND RELATION BETWEEN COVER AND COMPACTIFICATION

  • Lee, Sang-Deok;Kim, Chang-Il
    • 한국수학교육학회지시리즈B:순수및응용수학
    • /
    • 제3권2호
    • /
    • pp.163-171
    • /
    • 1996
  • Observing that a locally weakly Lindel$\"{o}$f space is a quasi-F space if and only if it has an F-base, we show that every dense weakly Lindel$\"{o}$f subspace of an almost-p-space is C-embedded, every locally weakly Lindel$\"{o}$f space with a cocompact F-base is a locally compact and quasi-F space and that if Y is a dense weakly Lindel$\"{o}$f subspace of X which has a cocompact F-base, then $\beta$Y and X are homeomorphic. We also show that for any a separating nest generated intersection ring F on a space X, there is a separating nest generated intersection ring g on $\phi_{Y}^{-1}$(X) such that QF(w(X, F)) and ($\phi_{Y}^{-1}$(X),g) are homeomorphic and $\phi_{Y}_{x}$(g$^#$)=F$^#$.

  • PDF

THE FOCK-DIRICHLET SPACE AND THE FOCK-NEVANLINNA SPACE

  • Cho, Hong Rae;Park, Soohyun
    • East Asian mathematical journal
    • /
    • 제38권5호
    • /
    • pp.643-647
    • /
    • 2022
  • Let F2 denote the space of entire functions f on ℂ that are square integrable with respect to the Gaussian measure $dG(z)={\frac{1}{\pi}}{e^{-{\mid}z{\mid}^2}}$, where dA(z) = dxdy is the ordinary area measure. The Fock-Dirichlet space $F^2_{\mathcal{D}}$ consists of all entire functions f with f' ∈ F2. We estimate Taylor coefficients of functions in the Fock-Dirichlet space. The Fock-Nevanlinna space $F^2_{\mathcal{N}}$ consists of entire functions that possesses just a bit more integrability than square integrability. In this note we prove that $F^2_{\mathcal{D}}=F^2_{\mathcal{N}}$.

Quasi-F 공간과 극소 Quasi-F cover의 역사적 배경 (Historical backgrounds of Quasi-F spaces and minimal quasi-F covers)

  • 김창일
    • 한국수학사학회지
    • /
    • 제18권4호
    • /
    • pp.113-124
    • /
    • 2005
  • 티코노프공간 X에 대하여 C(X)와 $C^*(X)$는 Riesz-공간이다 C(X)가 순서-코시완비일 필요충분한조건은 X가 quasi-F 공간이고, X가 컴팩트공간이며 QF(X)가 X의 극소 quasi-F cover일 때, C(X)의 순서-코시완비화와 C(QF(X))는 동형이다. 본 논문에서는 quasi-F 공간의 정의와 극소 quasi-F cover의 구성에 관한 동기 및 역사적 배경을 살펴본다.

  • PDF

A HAHN-BANACH EXTENSION THEOREM FOR ENTIRE FUNCTIONS OF NUCLEAR TYPE

  • Nishihara, Masaru
    • 대한수학회지
    • /
    • 제41권1호
    • /
    • pp.131-143
    • /
    • 2004
  • Let Ε and F be locally convex spaces over C. We assume that Ε is a nuclear space and F is a Banach space. Let f be a holomorphic mapping from Ε into F. Then we show that f is of uniformly bounded type if and only if, for an arbitrary locally convex space G containing Ε as a closed subspace, f can be extended to a holomorphic mapping from G into F.

F-CLOSED SPACES

  • Chae, Gyuihn;Lee, Dowon
    • Kyungpook Mathematical Journal
    • /
    • 제27권2호
    • /
    • pp.127-134
    • /
    • 1987
  • The purpose of this paper is to introduce a topological space named an F-closed space. This space is properly contained between an S-closed space [17] and a quasi H-closed space [14], and between a nearly compact space [15] and a quasi H-closed space. We will investigate properties of F-closed spaces, and improve some results in [2], [7] and [17].

  • PDF

한국어 단모음 8개에 대한 음향분석 - F1/F2 모음공간에서의 음향변수를 중심으로 - (An Acoustic Analysis on the Korean 8 Monophthongs - With Respect to the Acoustic Variables on the F1/F2 Vowel Space -)

  • 성철재
    • 한국음향학회지
    • /
    • 제23권6호
    • /
    • pp.454-461
    • /
    • 2004
  • This paper describes the acoustic characteristics of 8 Korean monophthongs. Two acoustic variables were newly manipulated the distance between Fl and F2 (Δ[F2-Fl]). which might be of help for the judgement of the vowel backness. and Euclidian distance between two vowels. [에] & [애] were observed to be merged in both male vowel space and the female's. respectively. The merger of [우] & [오], on the other hand, was only seen in the female space. In case of Fl, which concerns the vowel height. the scope of the females' was 1.36 times longer than that of the males' Regarding F2, which is related to the vowel backness. the females used a space 1.29 times longer than the males. The observation of Euclidian distance between the basic 3 vowels (이. 아. 우) showed that the females have longer distance than the males: [이-아] 1.25 times, [아-우] 1.45 times, and [이-우] 1.35 times. respectively.

NOTES ON THE SPACE OF DIRICHLET TYPE AND WEIGHTED BESOV SPACE

  • Choi, Ki Seong
    • 충청수학회지
    • /
    • 제26권2호
    • /
    • pp.393-402
    • /
    • 2013
  • For 0 < $p$ < ${\infty}$, ${\alpha}$ > -1 and 0 < $r$ < 1, we show that if $f$ is in the space of Dirichlet type $\mathfrak{D}^p_{p-1}$, then ${\int}_{1}^{0}M_{p}^{p}(r,f^{\prime})(1-r)^{p-1}rdr$ < ${\infty}$ and ${\int}_{1}^{0}M_{(2+{\alpha})p}^{(2+{\alpha})p}(r,f^{\prime})(1-r)^{(2+{\alpha})p+{\alpha}}rdr$ < ${\infty}$ where $M_p(r,f)=\[\frac{1}{2{\pi}}{\int}_{0}^{2{\pi}}{\mid}f(re^{it}){\mid}^pdt\]^{1/p}$. For 1 < $p$ < $q$ < ${\infty}$ and ${\alpha}+1$ < $p$, we show that if there exists some positive constant $c$ such that ${\parallel}f{\parallel}_{L^{q(d{\mu})}}{\leq}c{\parallel}f{\parallel}_{\mathfrak{D}^p_{\alpha}}$ for all $f{\in}\mathfrak{D}^p_{\alpha}$, then ${\parallel}f{\parallel}_{L^{q(d{\mu})}}{\leq}c{\parallel}f{\parallel}_{\mathcal{B}_p(q)}$ where $\mathcal{B}_p(q)$ is the weighted Besov space. We also find the condition of measure ${\mu}$ such that ${\sup}_{a{\in}D}{\int}_D(k_a(z)(1-{\mid}a{\mid}^2)^{(p-a-1)})^{q/p}d{\mu}(z)$ < ${\infty}$.

WEIGHTED COMPOSITION OPERATORS FROM F(p, q, s) INTO LOGARITHMIC BLOCH SPACE

  • Ye, Shanli
    • 대한수학회지
    • /
    • 제45권4호
    • /
    • pp.977-991
    • /
    • 2008
  • We characterize the boundedness and compactness of the weighted composition operator $uC_{\psi}$ from the general function space F(p, q, s) into the logarithmic Bloch space ${\beta}_L$ on the unit disk. Some necessary and sufficient conditions are given for which $uC_{\psi}$ is a bounded or a compact operator from F(p,q,s), $F_0$(p,q,s) into ${\beta}_L$, ${\beta}_L^0$ respectively.

PRINCIPAL FIBRATIONS AND GENERALIZED H-SPACES

  • Yoon, Yeon Soo
    • 충청수학회지
    • /
    • 제29권1호
    • /
    • pp.177-186
    • /
    • 2016
  • For a map $f:A{\rightarrow}X$, there are concepts of $H^f$-spaces, $T^f$-spaces, which are generalized ones of H-spaces [17,18]. In general, Any H-space is an $H^f$-space, any $H^f$-space is a $T^f$-space. For a principal fibration $E_k{\rightarrow}X$ induced by $k:X{\rightarrow}X^{\prime}$ from ${\epsilon}:PX^{\prime}{\rightarrow}X^{\prime}$, we obtain some sufficient conditions to having liftings $H^{\bar{f}}$-structures and $T^{\bar{f}}$-structures on $E_k$ of $H^f$-structures and $T^f$-structures on X respectively. We can also obtain some results about $H^f$-spaces and $T^f$-spaces in Postnikov systems for spaces, which are generalizations of Kahn's result about H-spaces.