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Mostrando ítems 1-10 de 29
Artículo
Thin sets of integers in Harmonic analysis and p-stable random Fourier series
(Springer, 2011-06)
We investigate the behavior of some thin sets of integers defined through random trigonometric polynomial when one replaces Gaussian or Rademacher variables by p-stable ones, with 1 < p < 2. We show that in one case this ...
Ponencia
Artículo
Geodesic Ptolemy spaces and fixed points
(Elsevier, 2011-01-01)
We prove that geodesic Ptolemy spaces with a continuous midpoint map are strictly convex. Moreover, we show that geodesic Ptolemy spaces with a uniformly continuous midpoint map are reflexive and that in such a setting ...
Artículo
Nevanlinna counting function and Carleson function of analytic maps
(Springer, 2011-10)
We show that the maximal Nevanlinna counting function and the Carleson function of analytic self-maps of the unit disk are equivalent, up to constants.
Artículo
Interface evolution: the Hele-Shaw and Muskat problems
(Princeton University, 2011)
We study the dynamics of the interface between two incompressible 2-D flows where the evolution equation is obtained from Darcy’s law. The free boundary is given by the discontinuity among the densities and viscosities of ...
Artículo
Weakly coercive mappings sharing a value
(Academy of Sciences of Czech Republic, Mathematical Institute, 2011)
Some sufficient conditions are provided that guarantee that the difference of a compact mapping and a proper mapping defined between any two Banach spaces over K has at least one zero. When conditions are strengthened, ...
Artículo
Some examples of matrix-valued orthogonal functions having a differential and an integral operator as eigenfunctions
(Elsevier, 2011-05)
The aim of this paper is to show some examples of matrix-valued orthogonal functions on the real line which are simultaneously eigenfunctions of a second-order differential operator of Schrödinger type and an integral ...
Artículo
A fixed point theorem for weakly Zamfirescu mappings
(Elsevier, 2011-03-01)
In [13] T. Zamfirescu, Fixed point theorems in metric spaces, Arch. Math. 23 (1972), 292–298. Zamfirescu gave a fixed point theorem that generalizes the classical fixed point theorems by Banach, Kannan and Chatterjea. In ...
Artículo
A proof of a trigonometric inequality. A glimpse inside the mathematical kitchen
(2011-09)
We prove the inequality ∞ ∑ k=1(−1) k+1 rk cos kφ k+2 < ∞ ∑ k=1 (−1) k+1 rk k+2 for 0 < r 1 and 0 < φ < π . For the case r = 1 we give two proofs. The first one is by means of a general numerical technique (Maximal Slope ...