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Permanent URI for this collectionhttps://hdl.handle.net/20.500.14288/6

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Indexed at: search.filters.indexed.TR DizinSubject: search.filters.subject.Mathematics

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Now showing 1 - 4 of 4
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    PublicationOpen Access
    A class of Banach algebras whose duals have the Schur property
    (TÜBİTAK, 1999) Mustafayev, H.; Department of Mathematics; Ülger, Ali; Faculty Member; Department of Mathematics; College of Sciences
    Call a commutative Banach algebra A a γ-algebra if it contains a bounded group Λ such that aco(Λ) contains a multiple of the unit ball of A. In this paper, first by exhibiting several concrete examples, we show that the class of γ-algebras is quite rich. Then, for a γ-algebra A, we prove that A* has the Schur property iff the Gelfand spectrum Σ of A is scattered iff A* = ap(A) iff A* = Span(Σ).
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    PublicationOpen Access
    Divisor function and bounds in domains with enough primes
    (Hacettepe Üniversitesi, 2019) Department of Mathematics; Göral, Haydar; Master Student; Department of Mathematics; College of Sciences
    In this note, first we show that there is no uniform divisor bound for the Bezout identity using Dirichlet's theorem on arithmetic progressions. Then, we discuss for which rings the absolute value bound for the Bezout identity is not trivial and the answer depends on the number of small primes in the ring.
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    PublicationOpen Access
    On elastic graph spines associated to quadratic Thurston maps
    (TÜBİTAK, 2022) Department of Mathematics; Yetişer, Ali Berkay; Faculty Member; Department of Mathematics; College of Sciences
    For a quadratic Thurston map having two distinct critical points and n postcritical points, we count the number of possible dynamical portraits. We associate elastic graph spines to several hyperbolic quadratic Thurston rational functions. These functions have four postcritical points, real coefficients, and invariant real intervals. The elastic graph spines are constructed such that each has embedding energy less than one. These are supporting examples to Dylan Thurston's recent positive characterization of rational maps. Using the same characterization, we prove that with a combinatorial restriction on the branched covering and a cycle condition on the dynamical portrait, a quadratic Thurston map with finite postcritical set of order n is combinatorially equivalent to a rational map. This is a special case of the Bernstein-Levy theorem.
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    PublicationOpen Access
    Linear connections on light-like manifolds
    (Scientific and Technological Research Council of Turkey (TUBITAK), 2008) Koçak, Ş.; Limoncu, M.; Department of Physics; Dereli, Tekin; Faculty Member; Department of Physics; College of Sciences; 201358
    It is well-known that a torsion-free linear connection on a light-like manifold (M, g) compatible with the degenerate metric g exists if and only if Rad(TM) is a Killing distribution. In case of existence, there is an infinitude of connections with none distinguished. We propose a method to single out connections with the help of a special set of 1-forms by the condition that the 1-forms become parallel with respect to this connection. Such sets of 1-forms could be regarded as an additional structure imposed upon the light-like manifold. We consider also connections with torsion and with non-metricity on light-like manifolds.