Approximation of Almost Diagonal Non-linear Maps by Lattice Lipschitz Operators


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Arnau R., Calabuig J. M., ERDOĞAN E., Sánchez Pérez E. A.

Bulletin of the Brazilian Mathematical Society, cilt.55, sa.1, 2024 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 55 Sayı: 1
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1007/s00574-024-00385-9
  • Dergi Adı: Bulletin of the Brazilian Mathematical Society
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, MathSciNet, zbMATH
  • Anahtar Kelimeler: 65D15, Diagonalisation, Lattice, Lipschitz operator, Non-linear map, Normed space, Primary 47J10, Secondary 41A65
  • Marmara Üniversitesi Adresli: Evet

Özet

Lattice Lipschitz operators define a new class of nonlinear Banach-lattice-valued maps that can be written as diagonal functions with respect to a certain basis. In the n-dimensional case, such a map can be represented as a vector of size n of real-valued functions of one variable. In this paper we develop a method to approximate almost diagonal maps by means of lattice Lipschitz operators. The proposed technique is based on the approximation properties and error bounds obtained for these operators, together with a pointwise version of the interpolation of McShane and Whitney extension maps that can be applied to almost diagonal functions. In order to get the desired approximation, it is necessary to previously obtain an approximation to the set of eigenvectors of the original function. We focus on the explicit computation of error formulas and on illustrative examples to present our construction.