Multi-component phase separation and small deformations of a spherical biomembrane

Fuente: arXiv
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Main Authors: Caetano, Diogo, Elliott, Charles M., Grasselli, Maurizio, Poiatti, Andrea
Format: Preprint
Published: 2024
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author Caetano, Diogo
Elliott, Charles M.
Grasselli, Maurizio
Poiatti, Andrea
author_facet Caetano, Diogo
Elliott, Charles M.
Grasselli, Maurizio
Poiatti, Andrea
contents We focus on the derivation and analysis of a model for multi-component phase separation occurring on biological membranes, inspired by observations of lipid raft formation. The model integrates local membrane composition with local membrane curvature, describing the membrane's geometry through a perturbation method represented as a graph over an undeformed Helfrich minimising surface, such as a sphere. The resulting energy consists of a small deformation functional coupled to a Cahn-Hilliard functional. By applying Onsager's variational principle, we obtain a multi-component Cahn-Hilliard equation for the vector $\boldsymbolφ$ of protein concentrations coupled to an evolution equation for the small deformation $u$ along the normal direction to the reference membrane. Then, in the case of a constant mobility matrix, we consider the Cauchy problem and we prove that it is (globally) well posed in a weak setting. We also demonstrate that any weak solution regularises in finite time and satisfies the so-called "strict separation property". This property allows usto show that any weak solution converges to a single stationary state by a suitable version of the Lojasiewicz-Simon inequality.
format Preprint
id arxiv_https___arxiv_org_abs_2410_05492
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Multi-component phase separation and small deformations of a spherical biomembrane
Caetano, Diogo
Elliott, Charles M.
Grasselli, Maurizio
Poiatti, Andrea
Analysis of PDEs
35B36, 35Q92, 92C15
We focus on the derivation and analysis of a model for multi-component phase separation occurring on biological membranes, inspired by observations of lipid raft formation. The model integrates local membrane composition with local membrane curvature, describing the membrane's geometry through a perturbation method represented as a graph over an undeformed Helfrich minimising surface, such as a sphere. The resulting energy consists of a small deformation functional coupled to a Cahn-Hilliard functional. By applying Onsager's variational principle, we obtain a multi-component Cahn-Hilliard equation for the vector $\boldsymbolφ$ of protein concentrations coupled to an evolution equation for the small deformation $u$ along the normal direction to the reference membrane. Then, in the case of a constant mobility matrix, we consider the Cauchy problem and we prove that it is (globally) well posed in a weak setting. We also demonstrate that any weak solution regularises in finite time and satisfies the so-called "strict separation property". This property allows usto show that any weak solution converges to a single stationary state by a suitable version of the Lojasiewicz-Simon inequality.
title Multi-component phase separation and small deformations of a spherical biomembrane
topic Analysis of PDEs
35B36, 35Q92, 92C15
url https://arxiv.org/abs/2410.05492