Análisis Matemático
https://hdl.handle.net/11441/10808
2019-02-22T12:38:35ZNonlinear Reynolds equations for non-Newtonian thin-film fluid flows over a rough boundary
https://hdl.handle.net/11441/83194
Nonlinear Reynolds equations for non-Newtonian thin-film fluid flows over a rough boundary
We consider a non-Newtonian fluid flow in a thin domain with thickness ηε and an oscillating top boundary of period ε. The flow is described by the 3D incompressible Navier-Stokes system with a nonlinear viscosity, being a power of the shear rate (power law) of flow index p, with 9/5 < p < +∞.
We consider the limit when the thickness tends to zero and we prove that the three characteristic regimes for Newtonian fluids are still valid for non-Newtonian fluids, i.e. Stokes roughness (ηε ≈ ε), Reynolds roughness (ηε << ε) and high-frequency roughness (ηε >> ε) regime. Moreover, we obtain different nonlinear Reynolds-type equations in each case.
2019-01-01T00:00:00ZLocal distribution of Rademacher series and function spaces
https://hdl.handle.net/11441/82389
Local distribution of Rademacher series and function spaces
2017-05-01T00:00:00ZAplicación de las trasnformaciones de semejanza a diversos problemas numéricos con matrices
https://hdl.handle.net/11441/81319
Aplicación de las trasnformaciones de semejanza a diversos problemas numéricos con matrices
1972-03-01T00:00:00ZKomlós' Theorem and the Fixed Point Property for affine mappings
https://hdl.handle.net/11441/81111
Komlós' Theorem and the Fixed Point Property for affine mappings
Assume that X is a Banach space of measurable functions for which Koml´os’ Theorem holds. We associate to any closed convex bounded subset C of X a coefficient t(C) which attains its minimum value when C is closed for the topology of convergence in measure and we prove some fixed point results for affine Lipschitzian mappings, depending on the value of t(C) ∈ [1, 2] and the value of the Lipschitz constants of the iterates. As a first consequence, for every L < 2, we deduce the existence of fixed points for affine uniformly L-Lipschitzian mappings defined on the closed unit ball of L1[0, 1]. Our main theorem also provides a wide collection of convex closed bounded sets in L
1([0, 1]) and in some other spaces of functions, which satisfy the fixed point property for affine nonexpansive mappings. Furthermore, this property is still
preserved by equivalent renormings when the Banach-Mazur distance is
small enough. In particular, we prove that the failure of the fixed point
property for affine nonexpansive mappings in L1(µ) can only occur in
the extremal case t(C) = 2. Examples are displayed proving that our
fixed point theorem is optimal in terms of the Lipschitz constants and
the coefficient t(C).
2018-12-01T00:00:00Z