Now showing items 1-10 of 10

    • Asymptotic greediness of the Haar system in the spaces Lp[0 , 1] , 1< p< ∞ 

      Albiac Alesanco, Fernando José Upna; Ansorena, José L.; Berná, Pablo M. (Springer, 2019)   Artículo / Artikulua  OpenAccess
      Our aim in this paper is to attain a sharp asymptotic estimate for the greedy constant Cg[H(p), Lp] of the (normalized) Haar system H(p) in Lp[0 , 1] for 1 < p < ∞. We will show that the super-democracy constant of H(p) ...
    • Building highly conditional almost greedy and quasi-greedy bases in Banach spaces 

      Albiac Alesanco, Fernando José Upna; Ansorena, José L.; Dilworth, S. J.; Kutzarova, Denka (Elsevier, 2019)   Artículo / Artikulua  OpenAccess
      It is known that for a conditional quasi-greedy basis B in a Banach space X, the associated sequence (k(m)[B](m=1)(infinity) of its conditionality constants verifies the estimate k(m)[B] = O(log m) and that if the reverse ...
    • Conditional quasi-greedy bases in non-superreflexive Banach spaces 

      Albiac Alesanco, Fernando José Upna; Ansorena, José L.; Wojtaszczyk, Przemyslaw (Springer, 2019)   Artículo / Artikulua  OpenAccess
      For a conditional quasi-greedy basis B in a Banach space, the associated conditionality constants km[B] verify the estimate km[B]=O(logm). Answering a question raised by Temlyakov, Yang, and Ye, several authors have studied ...
    • Embeddability of ℓp and bases in Lipschitz free p-spaces for 0 < p ≤ 1 

      Albiac Alesanco, Fernando José Upna; Ansorena, José L.; Cúth, Marek; Doucha, Michal (Elsevier, 2020)   Artículo / Artikulua
      Our goal in this paper is to continue the study initiated by the authors in of the geometry of the Lipschitz free p-spaces over quasimetric spaces for 0 < p ≤ 1, denoted Fp(M). Here we develop new techniques to show that, ...
    • Lipschitz free p-spaces for 0 < p < 1 

      Albiac Alesanco, Fernando José Upna; Ansorena, José L.; Cúth, Marek; Doucha, Michal (SpringerHebrew University Magnes Press, 2020)   Artículo / Artikulua
      This paper initiates the study of the structure of a new class of p-Banach spaces, 0 <p < 1, namely the Lipschitz free p-spaces (alternatively called Arens—Eells p-spaces) Fp(M) over p-metric spaces. We systematically ...
    • Non-superreflexivity of Garling sequence spaces and applications to the existence of special types of conditional bases 

      Albiac Alesanco, Fernando José Upna; Ansorena, José L.; Dilworth, S. J.; Kutzarova, Denka (Instytut Matematyczny, 2020)   Artículo / Artikulua  OpenAccess
      We settle in the negative the problem of the superreflexivity of Garling sequence spaces by showing that they contain a complemented subspace isomorphic to a non-superreflexive mixed-norm sequence space. As a by-product, ...
    • On certain subspaces of p for 0 < p ≤ 1 and their applications to conditional quasi-greedy bases in p-Banach spaces 

      Albiac Alesanco, Fernando José Upna; Ansorena, José L.; Wojtaszczyk, Przemyslaw (Springer, 2021)   Artículo / Artikulua
      We construct for each 0<p≤1 an infinite collection of subspaces of ℓp that extend the example of Lindenstrauss (Bull. Acad. Polon. Sci. Sér. Sci. Math. Astronom. Phys. 12, 539–542, 1964) of a subspace of ℓ1 with no ...
    • On perfectly homogeneous bases in quasi-Banach spaces 

      Albiac Alesanco, Fernando José Upna; Leránoz Istúriz, María Camino Upna (Hindawi Publishing Corporation, 2009)   Artículo / Artikulua  OpenAccess
      For 0 < p < infinity the unit vector basis of l(p) has the property of perfect homogeneity: it is equivalent to all its normalized block basic sequences, that is, perfectly homogeneous bases are a special case of symmetric ...
    • The Tsirelson space tau (p) has a unique unconditional basis up to permutation for 0 < p < 1 

      Albiac Alesanco, Fernando José Upna; Leránoz Istúriz, María Camino Upna (Hindawi Publishing Corporation, 2009)   Artículo / Artikulua  OpenAccess
      We show that the p-convexified Tsirelson space tau((p)) for 0 < p < 1 and all its complemented subspaces with unconditional basis have unique unconditional basis up to permutation. The techniques involved in the proof are ...
    • Unconditional and quasi-greedy bases in L-p with applications to Jacobi polynomials Fourier series 

      Albiac Alesanco, Fernando José Upna; Ansorena, José L.; Ciaurri, Óscar; Varona, Juan L. (European Mathematical Society, 2019)   Artículo / Artikulua  OpenAccess
      We show that the decreasing rearrangement of the Fourier series with respect to the Jacobi polynomials for functions in L-p does not converge unless p = 2. As a by-product of our work on quasi-greedy bases in L-p(µ), we ...