arXiv subjects

G. Chacón-Acosta

Publications and source records attributed to G. Chacón-Acosta.

4 recordsLinked to original sources

arXiv2019

Membrane stress and torque induced by Frank's nematic textures: A geometric perspective using surface-based constraints

An elastic membrane with embedded nematic molecules is considered as a model of anisotropic fluid membrane with internal ordering. By considering the geometric coupling between director field and membrane curvature, the nematic texture is shown to induce anisotropic stresses additional to Canham-Helfrich elasticity. Building upon differential geometry, analytical expressions are found for the membrane stress and torque induced by splaying, twisting and bending of the nematic director as described by the Frank energy of liquid crystals. The forces induced by prototypical nematic textures are visualized on the sphere and on cylindrical surfaces.

cond-mat.soft↗

arXiv2019

Thermal dissipation in two dimensional relativistic Fermi gases with a relaxation time model

The thermal transport properties of a two dimensional Fermi gas are explored, for the full range of temperatures and densities. The heat flux is established by solving the Uehling-Uhlebeck equation using a relaxation approximation given by Marle's collisional kernel and considering the temperature and chemical potential gradients as independent thermodynamic forces. It is shown that the corresponding transport coefficients are proportional to each other, which leads to the possibility of defining a generalized thermal force and a single transport coefficient. The behavior of such conductivity with the temperature and chemical potential is analyzed and a discussion on its dependence with the relaxation parameter is also included. The relevance and applications of the results are briefly addressed.

cond-mat.stat-mech↗

arXiv2018

Induced stresses in quasi-spherical elastic vesicles: local and global Laplace-Young law

On elastic spherical membranes, there is no stress induced by the bending energy and the corresponding Laplace-Young law does not involve the elastic bending stiffness. However, when considering an axially symmetrical perturbation that pinches the sphere, it induces nontrivial stresses on the entire membrane. In this paper we introduce a theoretical framework to examine the stress induced by perturbations of geometry around the sphere. We find the local balance force equations along the normal direction to the vesicle, and along the unit binormal, tangent to the membrane; likewise, the global balance force equation on closed loops is also examined. We analyze the distribution of stresses on the membrane as the budding transition occurs. For closed membranes we obtain the modified Young-Laplace law that appears as a consequence of this perturbation.

cond-mat.soft↗

arXiv2012

Exact solution to Fick-Jacobs equation

A relation between Fick-Jacobs and Schrödinger equation is shown. When the diffusion coefficient is constant, exact solutions for Fick-Jacobs equation are obtained. Using a change of variable the general case is studied.

math-ph↗