• 제목/요약/키워드: Semigroup of operators

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SEMIGROUP OF LIPSCHITZ OPERATORS

  • Lee, Young S.
    • Korean Journal of Mathematics
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    • 제14권2호
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    • pp.273-280
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    • 2006
  • Lipschitzian semigroup is a semigroup of Lipschitz operators which contains $C_0$ semigroup and nonlinear semigroup. In this paper, we establish the cannonical exponential formula of Lipschitzian semigroup from its Lie generator and the approximation theorem by Laplace transform approach to Lipschitzian semigroup.

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ON UDL DECOMPOSITIONS IN SEMIGROUPS

  • Lim, Yong-Do
    • 대한수학회지
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    • 제34권3호
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    • pp.633-651
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    • 1997
  • For a non-degenerate symmetric bilinear form $\sigma$ on a finite dimensional vector space E, the Jordan algebra of $\sigma$-symmetric operators has a symmetric cone $\Omega_\sigma$ of positive definite operators with respect to $\sigma$. The cone $C_\sigma$ of elements (x,y) \in E \times E with \sigma(x,y) \geq 0$ gives the compression semigroup. In this work, we show that in the sutomorphism group of the tube domain over $\Omega_\sigma$, this semigroup has a UDL and Ol'shanskii decompositions and is exactly the compression semigroup of $\Omega_sigma$.

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ON THE DIFFUSION OPERATOR IN POPULATION GENETICS

  • Choi, Won
    • Journal of applied mathematics & informatics
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    • 제30권3_4호
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    • pp.677-683
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    • 2012
  • W.Choi([1]) obtains a complete description of ergodic property and several property by making use of the semigroup method. In this note, we shall consider separately the martingale problems for two operators A and B as a detail decomposition of operator L. A key point is that the (K, L, $p$)-martingale problem in population genetics model is related to diffusion processes, so we begin with some a priori estimates and we shall show existence of contraction semigroup {$T_t$} associated with decomposition operator A.

DECOMPOSITION OF DIRICHLET FORMS ASSOCIATED TO UNBOUNDED DIRICHLET OPERATORS

  • Ko, Chul-Ki
    • 대한수학회보
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    • 제46권2호
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    • pp.347-358
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    • 2009
  • In [8], the author decomposed the Dirichlet form associated to a bounded generator G of a $weakly^*$-continuous, completely positive, KMS-symmetric Markovian semigroup on a von Neumann algebra M. The aim of this paper is to extend G to the unbounded generator using the bimodule structure and derivations.

BIPOLAR FUZZY SET THEORY APPLIED TO SUB-SEMIGROUPS WITH OPERATORS IN SEMIGROUPS

  • Kang, Mee-Kwang;Kang, Jeong-Gi
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제19권1호
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    • pp.23-35
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    • 2012
  • Given a set ${\Omega}$ and the notion of bipolar valued fuzzy sets, the concept of a bipolar ${\Omega}$-fuzzy sub-semigroup in semigroups is introduced, and related properties are investigated. Using bipolar ${\Omega}$-fuzzy sub-semigroups, bipolar fuzzy sub-semigroups are constructed. Conversely, bipolar ${\Omega}$-fuzzy sub-semigroups are established by using bipolar fuzzy sub-semigroups. A characterizations of a bipolar ${\Omega}$-fuzzy sub-semigroup is provided, and normal bipolar ${\Omega}$-fuzzy sub-semigroups are discussed. How the homomorphic images and inverse images of bipolar ${\Omega}$-fuzzy sub-semigroups become bipolar ${\Omega}$-fuzzy sub-semigroups are considered.

Unbounded Scalar Operators on Banach Lattices

  • deLaubenfels, Ralph
    • 호남수학학술지
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    • 제8권1호
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    • pp.1-19
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    • 1986
  • We show that a (possibly unbounded) linear operator, T, is scalar on the real line (spectral operator of scalar type, with real spectrum) if and only if (iT) generates a uniformly bounded semigroup and $(1-iT)(1+iT)^{-1}$ is scalar on the unit circle. T is scalar on [0, $\infty$) if and only if T generates a uniformly bounded semigroup and $(1+T)^{-1}$ is scalar on [0,1). By analogy with these results, we define $C^0$-scalar, on the real line, or [0. $\infty$), for an unbounded operator. We show that a generator of a positive-definite group is $C^0$-scalar on the real line. and a generator of a completely monotone semigroup is $C^0$-scalar on [0, $\infty$). We give sufficient conditions for a closed operator, T, to generate a positive-definite group: the sequence < $\phi(T^{n}x)$ > $_{n=0}^{\infty}$ must equal the moments of a positive measure on the real line, for sufficiently many positive $\phi$ in $X^{*}$, x in X. If the measures are supported on [0, $\infty$), then T generates a completely monotone semigroup. On a reflexive Banach lattice, these conditions are also necessary, and are equivalent to T being scalar, with positive projection-valued measure. T generates a completely monotone semigroup if and only if T is positive and m-dispersive and generates a bounded holomorphic semigroup.

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A REMARK ON INVARIANCE OF QUANTUM MARKOV SEMIGROUPS

  • Choi, Ve-Ni;Ko, Chul-Ki
    • 대한수학회논문집
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    • 제23권1호
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    • pp.81-93
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    • 2008
  • In [3, 9], using the theory of noncommutative Dirichlet forms in the sense of Cipriani [6] and the symmetric embedding map, authors constructed the KMS-symmetric Markovian semigroup $\{S_t\}_{t{\geq}0}$ on a von Neumann algebra $\cal{M}$ with an admissible function f and an operator $x\;{\in}\;{\cal{M}}$. We give a sufficient and necessary condition for x so that the semigroup $\{S_t\}_{t{\geq}0}$ acts separately on diagonal and off-diagonal operators with respect to a basis and study some results.

ON THE GENERALIZED ORNSTEIN-UHLENBECK OPERATORS WITH REGULAR AND SINGULAR POTENTIALS IN WEIGHTED Lp-SPACES

  • Imen Metoui
    • 대한수학회논문집
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    • 제39권1호
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    • pp.149-160
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    • 2024
  • In this paper, we give sufficient conditions for the generalized Ornstein-Uhlenbeck operators perturbed by regular potentials and inverse square potentials AΦ,G,V,c=∆-∇Φ·∇+G·∇-V+c|x|-2 with a suitable domain generates a quasi-contractive, positive and analytic C0-semigroup in Lp(ℝN , e-Φ(x)dx), 1 < p < ∞. The proofs are based on an Lp-weighted Hardy inequality and perturbation techniques. The results extend and improve the generation theorems established by Metoui [7] and Metoui-Mourou [8].