A Homomorphism Theorem for Bilinear Multipliers

In this paper we prove an abstract homomorphism theorem for bilinear multipliers in the setting of locally compact Abelian (LCA) groups. We also provide some applications. In particular, we obtain a bilinear abstract version of K. de Leeuw's theorem for bilinear multipliers of strong and weak type. We also obtain necessary conditions on bilinear multipliers on non-compact LCA groups, yielding boundedness for the corresponding operators on products of rearrangement invariant spaces. Our investigations extend some existing results in Euclidean spaces to the framework of general LCA groups, and yield new boundedness results for bilinear multipliers in quasi Banach spaces

Solvability of the Dirichlet, Neumann and the regularity problems for parabolic equations with H\"older continuous coefficients

We establish the $L^2$-solvability of Dirichlet, Neumann and regularity problems for divergence-form heat (or diffusion) equations with H\"older-continuous diffusion coefficients, on bounded Lipschitz domains in $\mathbb{R}^n$. This is achieved through the demonstration of invertibility of the relevant layer-potentials which is in turn based on Fredholm theory and a new systematic approach which yields suitable parabolic Rellich-type estimates

Transference of local to global L2L^2 maximal estimates for dispersive partial differential equations

In this paper we give an elementary proof for transference of local to global maximal estimates for dispersive PDEs. This is done by transferring local $L^2$ estimates for certain oscillatory integrals with rough phase functions, to the corresponding global estimates. The elementary feature of our approach is that it entirely avoids the use of the wave packet techniques which are quite common in this context, and instead is based on scalings and classical oscillatory integral estimates.Comment: 10 page

Endpoint estimates for bilinear pseudodifferential operators with symbol in BS^m_{1,1}

In this paper we establish some endpoint estimates for bilinearpseudodifferential operators with symbol in the class BS^m_{1,1}, involving the space of functions with local bounded mean oscillation bmo. As a consequence we also obtain an endpoint estimate of Kato-Ponce type.Comment: This is an improvement of the old version, following suggestion of anonymous referee(s

Capacidad Cardiovascular en Adultos Sedentarios Obesos sometidos a prueba de esfuerzo en banda sin fin con Protocolo de Bruce modificado en el Centro de Medicina de la Actividad Física y el Deporte, año 2012

El estilo de vida sedentario es uno de los principales factores de riesgo para enfermedades de alta prevalencia, como la diabetes tipo 2, las enfermedades cardiovasculares, la osteoporosis y algunos cánceres. (1). La asociación del sedentarismo con la actual pandemia de obesidad y con el síndrome metabólico (SM) es clara. En consecuencia, el sedentarismo es un factor asociado con una peor calidad de vida y un incremento de la mortalidad general