Rendiconti dell'Istituto di Matematica dell'Università di Trieste: an International Journal of Mathematics vol.30 (1998)

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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 13
  • Publication
    Irreducible unitary representations of a diffeomorphisms group of an infinite-dimensional real manifold
    (Università degli Studi di Trieste. Dipartimento di Scienze Matematiche, 1998)
    Lüdkovsky, S.V.
    Groups of diffeomorphisms $Diff_{\beta,\Upsilon}^{t}$ (M) of infinite-dimensionai real Banach manifolds M are defined. Their structure is studied. Irreducible unitary representations of a group of diffeomorphisms associated with quasi-invariant measures on a Banach manifold are constructed.
      759  490
  • Publication
    Determination of convex bodies from $\pm \infty$-chord functions
    (Università degli Studi di Trieste. Dipartimento di Scienze Matematiche, 1998)
    Soranzo, Alessandro
    We generalize the concept of i-chord function to the cases $i=+\infty$ and $i=-\infty$, and we extend two results concerning the determination of convex bodies from i-chord functions to those new values of i.
      722  385
  • Publication
    Twistor Bundles of Almost Symplectic Manifolds
    (Università degli Studi di Trieste. Dipartimento di Scienze Matematiche, 1998)
    Nannicini, Antonella
    In this paper we introduce the twistor bundle of a 2n-dimensional almost symplectic manifold M as the quotient bundle $\frac{P\left(M,Sp\left(2n\right)\right)}{U\left(n\right)}$. Given a symplectic connection on M we introduce a natural almost Hermitian structure on the twistor bundle and we prove that this structure is K$\ddot{\textrm{a}}$hler if and only if M is symplectic and the chosen connection has vanishing curvature and (0,2)-part of the torsion. Moreover we prove that in the case of $\mathbb{R}^{2n}$ with standard symplectic structure the twistor bundle turns out to be K$\ddot{\textrm{a}}$hler with constant scalar curvature for a certain class of symplectic connections.
      943  478
  • Publication
    Totally geodesic horizontally conformal maps
    (Università degli Studi di Trieste. Dipartimento di Scienze Matematiche, 1998)
    Mustafa, M.T.
    We obtain a characterization of totally geodesic horizontally conformal maps by a method which arises as a consequence of the Bochner technique for harmonic morphisms. As a geometric consequence we show that the existence of a non-constant harmonic morphism $\textrm{Ø}$ from a compact Riemannian manifold M$^{m}$ of non-negative Ricci curvature to a compact Riemannian manifold of non-positive scalar curvature, forces M$^{m}$ either to be a global Riemannian product of integral manifolds of vertical and horizontal distributions or to be covered by a global Riemannian product.
      969  457
  • Publication
    Complex foliations in generalized twistor spaces
    (Università degli Studi di Trieste. Dipartimento di Scienze Matematiche, 1998)
    Migliorini, Massimiliano
    ;
    Tommasini, Adriano
    We consider a natural almost complex distribution on the associated bundle $F^{\left(n\right)}M$ to the principal bundle of the g-orthogonal oriented frames on a Riemannian manifold (M, g), with standard fibre $\frac{SO\left(2n+k\right)}{U\left(n\right)\times SO\left(k\right)}$: we find necessary and sufficient conditions ensuring that the distribution is an almost complex foliation in $F^{\left(n\right)}M$ and we compute the Nijenhuis tensor. Finally, we characterize the local sections of $F^{\left(n\right)}M$.
      790  389