Journal•ISSN: 0030-6126
Osaka Journal of Mathematics
Osaka University
About: Osaka Journal of Mathematics is an academic journal. The journal publishes majorly in the area(s): Invariant (mathematics) & Thesaurus (information retrieval). It has an ISSN identifier of 0030-6126. Over the lifetime, 2689 publications have been published receiving 33116 citations.
Topics: Invariant (mathematics), Thesaurus (information retrieval), Ring (mathematics), Cohomology, Equivariant map
Papers published on a yearly basis
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TL;DR: In this paper, the least square estimate of f(xt) is given based on the observations (zτ, 0<τ
Abstract: The general nonlinear filtering or estimation problem may be described as follows. xty (0
386 citations
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TL;DR: On definit une structure de Riemann tres naturelle sur l'espace de toutes les metriques de Kahler dans une classe de cohomologie fixee d'une variete de Kahlers compacte donnee as discussed by the authors.
Abstract: On definit une structure de Riemann tres naturelle sur l'espace de toutes les metriques de Kahler dans une classe de cohomologie fixee d'une variete de Kahler compacte donnee
339 citations
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TL;DR: In this paper, the authors considered the problem of determining homogeneous real hypersurfaces in a complex projective space Pn(C) of complex dimension n(^>2) which are orbits under analytic subgroups of the projective unitary group PU(n-\\-\\)>.
Abstract: The purpose of this paper is to determine those homogeneous real hypersurfaces in a complex projective space Pn(C) of complex dimension n(^>2) which are orbits under analytic subgroups of the projective unitary group PU(n-\\-\\)> and to give some characterizations of those hypersurfaces. In § 1 from each effective Hermitian orthogonal symmetric Lie algebra of rank two we construct an example of homogeneous real hypersurface in Pn(C)y which we shall call a model space in Pn(C). In §2 we show that the class of all homogeneous real hypersurfaces in Pn{C) that are orbits under analytic subgroups of PU(n-\\-l) is exhausted by all model spaces. In §§3 and 4 we give some conditions for a real hypersurface in Pn(C) to be an orbit under an analytic subgroup of PU(n-\\-l) and in the course of proof we obtain a rigidity theorem in Pn(C) analogous to one for hypersurfaces in a real space form. The author would like to express his hearty thanks to Professor T. Takahashi for valuable discussions with him and his constant encouragement, and to Professor M. Takeuchi who made an original complicated proof of Lemma 2.3 short and clear.
316 citations
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302 citations
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TL;DR: In this paper, the main theorem of T. Yamada [10] was modified to make it more convenient for applications, and a comparison theorem for one-dimensional projection of a diffusion process was obtained.
Abstract: Introduction. Comparison theorem for solutions of stochastic differential equations was discussed by A.V. Skorohod [9] and T. Yamada [10], In §1, we will modify the main theorem of T. Yamada [10] so that it is more convenient for applications. As an application, we discuss in §2 some stochastic optimal control problem which was recently studied by V.E. Benes [1] using different methods. In §3, we obtain some comparison theorem for one-dimensional projection of a diffusion process. As an example of applications, we see that Hashiminsky's test for explosion ([3], [7]) is obtained simply from a well known one-dimensional result.
293 citations