## Search

Now showing items 1-10 of 38

#### Singular Perturbation of the Dirac Hamiltonian

(2017-12-15)

This thesis is devoted to the study of the Dirac Hamiltonian perturbed by delta-type potentials and Coulomb-type potentials.
We analysed the delta-shell interaction on bounded and smooth domains and its approximation by ...

#### Klein's Paradox and the Relativistic $\delta$-shell Interaction in $\mathbb{R}^3$

(Analysis & PDE, 2017-11)

Under certain hypothesis of smallness of the regular potential $\mathbf{V}$, we prove that the Dirac operator in $\mathbb{R}^3$ coupled with a suitable re-scaling of $\mathbf{V}$, converges in the strong resolvent sense ...

#### Sphere-valued harmonic maps with surface energy and the K13 problem

(Advances in the Calculus of Variations, 2017-11)

We consider an energy functional motivated by the celebrated K13 problem in the Oseen-Frank theory of nematic liquid crystals. It is defined for sphere-valued functions and appears as the usual Dirichlet energy with an ...

#### On a hyperbolic system arising in liquid crystal modelling

(Journal of Hyperbolic Differential Equations, 2017-11)

We consider a model of liquid crystals, based on a nonlinear hyperbolic system of
differential equations, that represents an inviscid version of the model proposed by Qian
and Sheng. A new concept of dissipative solution ...

#### Global well-posedness and twist-wave solutions for the inertial Qian-Sheng model of liquid crystals

(Journal of Differential Equations, 2017-10-02)

We consider the inertial Qian-Sheng model of liquid crystals which couples a hyperbolic-type equation involving a second-order material derivative with a forced incompressible Navier-Stokes system. We study the energy law ...

#### Asymptotic behaviour for fractional diffusion-convection equations

(2017-10)

We consider a convection-diffusion model with linear fractional diffusion in the sub-critical range. We prove that the large time asymptotic behavior of the solution is given by the unique entropy solution of the convective ...

#### Existence of weak solutions for a general porous medium equation with nonlocal pressure

(submitted, 2017-10)

We study the general nonlinear diffusion equation $u_t=\nabla\cdot (u^{m-1}\nabla (-\Delta)^{-s}u)$ that describes a flow through a porous medium which is driven by a nonlocal pressure. We consider constant parameters ...

#### Three-dimensional coarsening dynamics of a conserved, nematic liquid crystal-isotropic fluid mixture

(Journal of Non-Newtonian Fluid Mechanics, 2017-09)

We present a numerical investigation of the three-dimensional coarsening dynamics of a nematic liquid crystal-isotropic fluid mixture using a conserved phase field model. The model is a coupled system for a generalized ...

#### The relativistic spherical $\delta$-shell interaction in $\mathbb{R}^3$: spectrum and approximation

(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 ...

#### An efficient multigrid strategy for large-scale molecular mechanics optimization

(Journal of Computational Physics, 2017-08-01)

Static mechanical properties of materials require large-scale nonlinear optimization of the molecular mechanics model under various controls. This paper presents an efficient multigrid strategy to solve such problems. This ...