Journal of the Mathematical Society of Japan
Online ISSN : 1881-1167
Print ISSN : 0025-5645
ISSN-L : 0025-5645
Volume 63, Issue 1
Displaying 1-11 of 11 articles from this issue
  • Setsuro Fujiié, Amina Lahmar-Benbernou, André Martinez
    2011 Volume 63 Issue 1 Pages 1-78
    Published: 2011
    Released on J-STAGE: February 25, 2011
    JOURNAL FREE ACCESS
    We consider the semiclassical Schrödinger operator with a well in an island potential, on which we assume smoothness only, except near infinity. We give the asymptotic expansion of the imaginary part of the shape resonance at the bottom of the well. This is a generalization of the result by Helffer and Sjöstrand [HeSj1] in the globally analytic case. We use an almost-analytic extension in order to continue the WKB solution coming from the well beyond the caustic set, and, for the justification of the accuracy of this approximation, we develop some refined microlocal arguments in h-dependent small regions.
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  • Jörg Brendle, Benedikt Löwe
    2011 Volume 63 Issue 1 Pages 137-151
    Published: 2011
    Released on J-STAGE: February 25, 2011
    JOURNAL FREE ACCESS
    In this paper, we are considering the Baire property of the eventually different topology as a regularity property for sets of reals and investigate the logical strength of the statements “Every Δ12 set has the Baire property in the eventually different topology” and “Every Σ12 set has the Baire property in the eventually different topology”. The latter statement turns out to be equivalent to “ω1 is inaccessible by reals”.
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  • Fumiya Morishita, Osamu Saeki
    2011 Volume 63 Issue 1 Pages 153-162
    Published: 2011
    Released on J-STAGE: February 25, 2011
    JOURNAL FREE ACCESS
    For a given closed surface, we study height functions with three critical values associated with immersions of the surface into 3-space, where the critical points may not be non-degenerate. We completely characterize the numbers of critical points corresponding to the three critical values that can be realized by such height functions. We also study the cases where the immersion can be replaced by an embedding or the critical points are all non-degenerate. Similar problems are studied for distance functions as well.
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  • Reinhard Farwig, Šárka Nečasová, Jiř& ...
    2011 Volume 63 Issue 1 Pages 163-194
    Published: 2011
    Released on J-STAGE: February 25, 2011
    JOURNAL FREE ACCESS
    We consider the spectrum of the Stokes operator with and without rotation effect for the whole space and exterior domains in Lq-spaces. Based on similar results for the Dirichlet-Laplacian on Rn, n ≥ 2, we prove in the whole space case that the spectrum as a set in C does not change with q ∈ (1,∞), but it changes its type from the residual to the continuous or to the point spectrum with q. The results for exterior domains are less complete, but the spectrum of the Stokes operator with rotation mainly is an essential one, consisting of infinitely many equidistant parallel half-lines in the left complex half-plane. The tools are strongly based on Fourier analysis in the whole space case and on stability properties of the essential spectrum for exterior domains.
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  • Satoru Fukasawa
    2011 Volume 63 Issue 1 Pages 195-209
    Published: 2011
    Released on J-STAGE: February 25, 2011
    JOURNAL FREE ACCESS
    For a plane curve, a point in the projective plane is said to be Galois when the point projection induces a Galois extension of function fields. We completely classify plane curves with infinitely many outer Galois points.
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  • Toshiyuki Kikuta, Shoyu Nagaoka
    2011 Volume 63 Issue 1 Pages 211-238
    Published: 2011
    Released on J-STAGE: February 25, 2011
    JOURNAL FREE ACCESS
    We generalize the notion of modular forms mod p to the case of Hermitian modular forms. Moreover we determine the structure of the algebra of degree 2 Hermitian modular forms mod p in the cases that the corresponding quadratic field is Q($¥sqrt{-1}$) and Q($¥sqrt{-3}$).
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  • Haruya Mizutani
    2011 Volume 63 Issue 1 Pages 239-261
    Published: 2011
    Released on J-STAGE: February 25, 2011
    JOURNAL FREE ACCESS
    We study the time decay of scattering solutions to one-dimensional Schrödinger equations and prove a weighted dispersive estimate with stronger time decay than the case of unweighted estimates for the non-resonant state. Furthermore asymptotic expansions in time of scattering solutions are given. The key of the proof is the study of the Fourier properties of the Jost functions. We improve the Fourier properties of the Jost functions obtained by D'Ancona and Fanelli [2].
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  • Ryuji Kajikiya
    2011 Volume 63 Issue 1 Pages 263-294
    Published: 2011
    Released on J-STAGE: February 25, 2011
    JOURNAL FREE ACCESS
    A sublinear elliptic equation whose coefficient is singular on the boundary is studied in any bounded domain Ω under the zero Dirichlet boundary condition. It is proved that the equation has a unique positive solution and infinitely many sign-changing solutions which belong to C1($¥overline{¥Omega}$) or C2(¥overline{¥Omega}$). Moreover, it is proved that the solutions have the higher order regularity corresponding to the smoothness of the coefficient.
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  • Xuan Thinh Duong, Lixin Yan
    2011 Volume 63 Issue 1 Pages 295-319
    Published: 2011
    Released on J-STAGE: February 25, 2011
    JOURNAL FREE ACCESS
    Let (X, d, μ) be a metric measure space endowed with a distance d and a nonnegative Borel doubling measure μ. Let L be a non-negative self-adjoint operator on L2(X). Assume that the semigroup e-tL generated by L satisfies the Davies-Gaffney estimates. Let HpL(X) be the Hardy space associated with L. We prove a Hörmander-type spectral multiplier theorem for L on HpL(X) for 0 < p < ∞: the operator m(L) is bounded from HpL(X) to HpL(X) if the function m possesses s derivatives with suitable bounds and s > n (1/p-1/2) where n is the “dimension” of X. By interpolation, m(L) is bounded on HpL(X) for all 0 < p < ∞ if m is infinitely differentiable with suitable bounds on its derivatives. We also obtain a spectral multiplier theorem on Lp spaces with appropriate weights in the reverse Hölder class.
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  • Raza Lahiani, Carine Molitor-Braun
    2011 Volume 63 Issue 1 Pages 321-361
    Published: 2011
    Released on J-STAGE: February 25, 2011
    JOURNAL FREE ACCESS
    Let N be a connected, simply connected nilpotent Lie group with Lie algebra $¥mathfrak{n}$ and let $¥mathscr{W}$ be a submanifold of $¥mathfrak{n}^*$ such that the dimension of all polarizations associated to elements of $¥mathscr{W}$ is fixed. We choose $(¥mathfrak{p}(w))_{w¥in ¥mathscr{W}}$ and $(¥mathfrak{p}'(w))_{w¥in ¥mathscr{W}}$ two smooth families of polarizations in $¥mathfrak{n}$. Let πw = indP(w)Nχw and π′w = indP′(w)Nχw be the corresponding induced representations, which are unitary and irreducible. It is well known that πw and π′w are unitary equivalent. In this paper, we prove the existence of a smooth family of intertwining operator (Tw)w for theses representations, where w runs through an appropriate non-empty relatively open subset of $¥mathscr{W}$. The intertwining operators are given by an explicit formula.
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  • Osamu Ikawa
    2011 Volume 63 Issue 1 Pages 79-136
    Published: 2011
    Released on J-STAGE: February 25, 2011
    JOURNAL FREE ACCESS
    We introduce the notion of symmetric triad, which is a generalization of the notion of irreducible root system, and study its fundamental properties. Applying these results, we study the orbit spaces of Hermann actions on compact symmetric spaces.
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