Rendiconti dell'Istituto di Matematica dell'Università di Trieste: an International Journal of Mathematics vol.38 (2006)

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Editorial policy The journal Rendiconti dell’Istituto di Matematica dell’università di Trieste publishes original articles in all areas of mathematics. Special regard is given to research papers, but attractive expository papers may also be considered for publication. The journal usually appears in one issue per year. Additional issues may however be published. In particular, the Managing Editors may consider the publication of supplementary volumes related to some special events, like conferences, workshops, and advanced schools. All submitted papers will be refereed. Manuscripts are accepted for review with the understanding that the work has not been published before and is not under consideration for publication elsewhere. Our journal can be obtained by exchange agreements with other similar journals.

Instructions for Authors Authors are invited to submit their papers by e-mail directly to one of the Managing Editors in PDF format. All the correspondence regarding the submission and the editorial process of the paper are done by e-mail. Papers have to be written in one of the following languages: English, French, German, or Italian. Abstracts should not exceed ten printed lines, except for papers written in French, German, or Italian, for which an extended English summary is required. After acceptance, manuscripts have to be prepared in LaTeX using the style rendiconti.cls which can be downloaded from the web page. Any figure should be recorded in a single PDF, PS (PostScript), or EPS (Encapsulated PostScript) file.

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Recent Submissions

Now showing 1 - 5 of 11
  • Publication
    On some Semilinear Periodic Parabolic Problems
    (EUT Edizioni Università di Trieste, 2006)
    Godoy, Tomas
    ;
    Kaufmann, Uriel
    Let $\Omega \subset \mathbb R^N$ a smooth bounded domain. We study existence and nonexistence of positive solutions for some semilinear Dirichlet periodic parabolic problems of the form $Lu = h(x,t,u)$ in $\Omega\times \mathbb R$ for a class of Caratheodory functions $h : \Omega\times \mathbb R \times [0,\infty) \rightarrow \mathbbR$ such that h (., 0) = 0 and $\lim_{\xi\rightarrow 0^+}\xi^{ −1}h (.,\xi) = 0$ or $-\infty$. All results remain true for the corresponding elliptic problems.
      888  465
  • Publication
    A Note on Gevrey Well-Posedness for the Operator $\partial^2_t - a(t)\partial _x(b(t,x)\partial_x)$
    (EUT Edizioni Università di Trieste, 2006)
    Del Santo, Daniele
    We use a Littlewood-Paley decomposition to obtain a Gevrey-well-posedness result for a weakly hyperbolic equation in one space variable with coefficients depending also on x.
      736  394
  • Publication
    Algebraic Aspects of Commutation of Linear Operators up to a Factor
    (EUT Edizioni Università di Trieste, 2006)
    Bellonotto, B.
    ;
    Teppati, Giancarlo
    When representing projective geometry by means of a vector space, commutativity can be replaced by commutativity up to a factor. This feature was investigated by F. Cecioni under very weak assumptions, but it is hard to generalize the methods of [4] to a wider algebraic context. In this note, we develop the independent treatment of H. Weyl, and extend the approach of to non-commutative rings under suitable assumptions on the endomorphisms. From this point of view, we show that commutativity of operators up to a non-trivial factor is an exceptional phenomenon in comparison to strict commutativity.
      841  577
  • Publication
    Hyperbolic Knots and Links with a Common Cyclic Branched Covering: Known Results and Open Problems
    (EUT Edizioni Università di Trieste, 2006)
    Zimmermann, Bruno P.
    We give a survey on recent progress and remaining open problems on the number and the geometry of knots and links which have a hyperbolic 3-manifold M as a common cyclic branched covering. This is strongly related to the algebra and the geometry of the finite isometry group G of M, and it naturally divides into the two cases G solvable and G non-solvable. The solvable case is relatively well understood whereas the non- solvable case remains somewhat mysterious.
      848  423
  • Publication
    The Transmission Acoustic Scattering Problem for Bi-Spheres in Low-Frequency Regime
    (EUT Edizioni Università di Trieste, 2006)
    Arnaoudov, Iani
    ;
    Venkov, George
    An acoustically soft sphere covered by a penetrable eccentric spherical shell disturbs the propagation of an incident plane wave field. It is shown that there exists exactly one bispherical coordinate system that describes the given geometry. The incident wave is assumed to have a wavelength which is much larger than the characteristic dimension of the scatterer and thus the low-frequency approximation method is applicable to the scattering problem. The incomplete R-separation of variables in bispherical coordinates and the normal differentiation involved in the transmission boundary conditions lead to a three-term recurrence relation for the series coefficients corresponding to the scattered fields. Thus, the potential boundary-value problem for the leading low-frequency approximations is reduced to infinite tridiagonal linear systems, which are solved analytically.
      814  515