Now showing items 103-122 of 160

    • A quantitative approach to weighted Carleson condition 

      Rivera-Ríos I.P. (Concrete Operators, 2017-05-05)
      Quantitative versions of weighted estimates obtained by F. Ruiz and J.L. Torrea for the operator \[ \mathcal{M}f(x,t)=\sup_{x\in Q,\,l(Q)\geq t}\frac{1}{|Q|}\int_{Q}|f(x)|dx \qquad x\in\mathbb{R}^{n}, \, t \geq0 \] are ...
    • Quantitative weighted estimates for rough homogeneous singular integrals 

      Hytönen T.P.; Roncal L.; Tapiola O. (Israel Journal of Mathematics, 2017-03-11)
      We consider homogeneous singular kernels, whose angular part is bounded, but need not have any continuity. For the norm of the corresponding singular integral operators on the weighted space $L^2(w)$, we obtain a bound ...
    • Quantitative weighted estimates for Rubio de Francia's Littlewood--Paley square function 

      Garg R.; Roncal L.; Shrivastava S. (Journal of Geometric Analysis, 2019-12)
      We consider the Rubio de Francia's Littlewood--Paley square function associated with an arbitrary family of intervals in $\mathbb{R}$ with finite overlapping. Quantitative weighted estimates are obtained for this operator. ...
    • Quantitative weighted estimates for singular integrals and commutators 

      Rivera-Ríos I.P. (2018-02-27)
      In this dissertation several quantitative weighted estimates for singular integral op- erators, commutators and some vector valued extensions are obtained. In particular strong and weak type $(p, p)$ estimates, Coifman-Fe ...
    • Quantitative weighted mixed weak-type inequalities for classical operators 

      Ombrosi S.; Pérez C.; Recchi J. (Indiana University Mathematics Journal, 2016-06-30)
      We improve on several mixed weak type inequalities both for the Hardy-Littlewood maximal function and for Calderón-Zygmund operators. These type of inequalities were considered by Muckenhoupt and Wheeden and later on by ...
    • Reconstruction from boundary measurements for less regular conductivities 

      García A.; Zhang G. (2016-10-01)
      In this paper, following Nachman's idea [14] and Haberman and Tataru's idea [9], we reconstruct $C^1$ conductivity $\gamma$ or Lipchitz conductivity $\gamma$ with small enough value of $|\nabla log\gamma|$ in a Lipschitz ...
    • Reconstruction of the Derivative of the Conductivity at the Boundary 

      Ponce-Vanegas F. (2019-08)
      We describe a method to reconstruct the conductivity and its normal derivative at the boundary from the knowledge of the potential and current measured at the boundary. This boundary determination implies the uniqueness ...
    • Regularity of fractional maximal functions through Fourier multipliers 

      Beltran D.; Ramos J. P.; Saari O. (2018)
      We prove endpoint bounds for derivatives of fractional maximal functions with either smooth convolution kernel or lacunary set of radii in dimensions $n \geq 2$. We also show that the spherical fractional maximal function ...
    • Relativistic Hardy Inequalities in Magnetic Fields 

      Fanelli L.; Vega L.; Visciglia N. (Journal of Statistical Physics, 2014-12-31)
      We deal with Dirac operators with external homogeneous magnetic fields. Hardy-type inequalities related to these operators are investigated: for a suitable class of transversal magnetic fields, we prove a Hardy inequality ...
    • The relativistic spherical $\delta$-shell interaction in $\mathbb{R}^3$: spectrum and approximation 

      Mas A.; Pizzichillo F. (Journal of Mathematical Physics, 2017-08-03)
      This note revolves on the free Dirac operator in $\mathbb{R}^3$ and its $\delta$-shell interaction with electrostatic potentials supported on a sphere. On one hand, we characterize the eigenstates of those couplings by ...
    • Reverse Hölder Property for Strong Weights and General Measures 

      Luque T.; Pérez C.; Rela E. (Journal of Geometric Analysis, 2016-06-30)
      We present dimension-free reverse Hölder inequalities for strong $A^{\ast}_p$ weights, $1 \le p < \infty$. We also provide a proof for the full range of local integrability of $A^{\ast}_1$ weights. The common ingredient ...
    • Robust numerical methods for nonlocal (and local) equations of porous medium type. Part II: Schemes and experiments 

      Del Teso F.; Endal J.; Jacobsen E.R. (SIAM Journal on Numerical Analysis, 2018)
      \noindent We develop a unified and easy to use framework to study robust fully discrete numerical methods for nonlinear degenerate diffusion equations $$ \partial_t u-\mathfrak{L}[\varphi(u)]=f(x,t) \qquad\text{in}\qquad ...
    • Self-Adjoint Extensions for the Dirac Operator with Coulomb-Type Spherically Symmetric Potentials 

      Cassano B.; Pizzichillo F. (Letters in Mathematical Physics, 2018)
      We describe the self-adjoint realizations of the operator $H:=-i\alpha\cdot \nabla + m\beta + \mathbb V(x)$, for $m\in\mathbb R $, and $\mathbb V(x)= |x|^{-1} ( \nu \mathbb{I}_4 +\mu \beta -i \lambda \alpha\cdot{x}/{|x|}\,\beta)$, ...
    • Self-similar dynamics for the modified Korteweg-de Vries equation 

      Correia S.; Côte R.; Vega L. (2019-04-09)
      We prove a local well posedness result for the modified Korteweg-de Vries equa- tion in a critical space designed so that is contains self-similar solutions. As a consequence, we can study the flow of this equation around ...
    • Sharp bounds for the ratio of modified Bessel functions 

      Zheng S.; Yang Z-H. (Mediterranean Journal of Mathematics, 2017-06-21)
      Let $I_{\nu }\left( x\right) $ be the modified Bessel functions of the first kind of order $\nu $, and $S_{p,\nu }\left( x\right) =W_{\nu }\left( x\right) ^{2}-2pW_{\nu }\left( x\right) -x^{2}$ with $W_{\nu }\left( x\right) ...
    • Sharp exponential localization for eigenfunctions of the Dirac Operator 

      Cassano B. (2018)
      We determine the fastest possible rate of exponential decay at infinity for eigenfunctions of the Dirac operator $\mathcal D_n + \mathbb V$, being $\mathcal D_n$ the massless Dirac operator in dimensions $n=2,3$ and ...
    • Sharp reverse Hölder inequality for Cp weights and applications 

      Canto J. (Journal of Geometric Analysis, 2020)
      We prove an appropriate sharp quantitative reverse Hölder inequality for the $C_p$ class of weights fromwhich we obtain as a limiting case the sharp reverse Hölder inequality for the $A_\infty$ class of weights (Hytönen ...
    • Sharp weighted estimates involving one supremum 

      Li K. (Comptes Rendus Mathematique, 2017-07)
      In this note, we study the sharp weighted estimate involving one supremum. In particular, we give a positive answer to an open question raised by Lerner and Moen. We also extend the result to rough homogeneous singular ...
    • Shear flow dynamics in the Beris-Edwards model of nematic liquid crystals 

      Murza A.C.; Teruel A.E.; Zarnescu A. (Proceedings of the Royal Society A-Mathematical, Physical and Engineering Sciences, 2018-02-14)
      We consider the Beris-Edwards model describing nematic liquid crystal dynamics and restrict to a shear flow and spatially homogeneous situation. We analyze the dynamics focusing on the effect of the flow. We show that in ...
    • Shell interactions for Dirac operators: On the point spectrum and the confinement 

      Arrizabalaga N.; Mas A.; Vega L. (SIAM Journal on Mathematical Analysis, 2015-12-31)
      Spectral properties and the confinement phenomenon for the coupling $H + V$ are studied, where $H =-i\alpha \cdot \nabla + m\beta$ is the free Dirac operator in $\mathbb{R}^3$ and $V$ is a measure-valued potential. The ...