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Mostrando ítems 1-10 de 11
Artículo
Some new properties of composition operators associated with lens maps
(Springer, 2013-05)
We give examples of results on composition operators connected with lens maps. The first two concern the approximation numbers of those operators acting on the usual Hardy space H2. The last ones are connected with ...
Artículo
Compact composition operators on the Dirichlet space and capacity of sets of contact points
(Elsevier, 2013-02-15)
We prove several results about composition operators on the Dirichlet space D⁎. For every compact set K⊆∂D of logarithmic capacity , there exists a Schur function φ both in the disk algebra A(D) and in D⁎ such that the ...
Artículo
On the Muskat problem: global in time results in 2D and 3D
(Johns Hopkins University Press, 2016-12)
This paper considers the three dimensional Muskat problem in the stable regime. We obtain a conservation law which provides an L2 maximum principle for the fluid interface. We also show global in time existence for strong ...
Artículo
Sharp estimates of the one-dimensional boundary control cost for parabolic systems and application to the N-dimensional boundary null controllability in cylindrical domains
(Society for Industrial and Applied Mathematics, 2014)
In this paper we consider the boundary null controllability of a system of n parabolic equations on domains of the form Ω = (0, π) × Ω2 with Ω2 a smooth domain of RN−1, N > 1. When the control is exerted on {0} × ω2 with ...
Artículo
Infinitesimal Carleson property for weighted measures induced by analytic self-maps of the unit disk
(Springer, 2013-08)
We prove that, for every α>−1, the pull-back measure φ(Aα) of the measure dAα(z)=(α+1)(1−|z|2)αdA(z), where A is the normalized area measure on the unit disk D, by every analytic self-map φ:D→D is not only an (α+2)-Carleson ...
Artículo
Finite element discretization of the Stokes and Navier-Stokes equations with boundary conditions on the pressure
(Society for Industrial and Applied Mathematics, 2015)
We consider the Stokes and Navier–Stokes equations with boundary conditions of Dirichlet type on the velocity on one part of the boundary and involving the pressure on the rest of the boundary. We write the variational ...
Artículo
A duality approach to the symmetry of Bernstein-Sato polynomials of free divisors
(Elsevier, 2015-08-20)
In this paper we prove that the Bernstein-Sato polynomial of any free divisor for which the D[s]-module D[s]h s admits a Spencer logarithmic resolution satisfies the symmetry property b(−s−2) = ±b(s). This applies in ...
Artículo
Numerical investigation of algebraic oceanic turbulent mixing-layer models
(Copernicus Publications, 2013-11-06)
In this paper we investigate the finite-time and asymptotic behaviour of algebraic turbulent mixing-layer models by numerical simulation. We compare the performances given by three different settings of the eddy viscosity. ...
Artículo
Stability of solitary waves in the nonlinear Dirac equation with arbitrary nonlinearity
(American Physical Society, 2014)
We consider the nonlinear Dirac equation in 1 + 1 dimension with scalar-scalar self interaction g2κ+1(Ψ¯¯¯Ψ)κ+1 and with mass m. Using the exact analytic form for rest frame solitary waves of the form Ψ(x,t)=ψ(x)e−iωt for ...
Artículo
On approximation numbers of composition operators
(Elsevier, 2012-04)
We show that the approximation numbers of a compact composition operator on the weighted Bergman spaces Bα of the unit disk can tend to 0 arbitrarily slowly, but that they never tend quickly to 0: they grow at ...