Gamma Convergence of Partially Segregated Elliptic Systems
Farid Bozorgnia, Avetik Arakelyan
TL;DR
The paper proves that penalized energies modeling partially segregated, three-component elliptic systems in planar domains Gamma-converge to a constrained Dirichlet energy as the penalty parameter vanishes. The authors establish a liminf inequality via compactness and lower semicontinuity, and construct recovery sequences by a detailed geometric decomposition into bulk, interface, and triple-junction regions, including boundary layers and curvature corrections. They treat Type I–III interfaces with TanH-type transition profiles and Type IV triple junctions with polar-coordinate sector constructions, showing interface energies scale as $O(\sqrt{\varepsilon})$ and junction energies as $O(\varepsilon^{1/4})$, respectively. A global partition of unity assembles the recovery sequences while preserving the constraint $u_1^\varepsilon u_2^\varepsilon u_3^\varepsilon=0$, thereby yielding the desired limsup inequality. Together, these results provide a rigorous variational bridge between penalized and constrained formulations for three-phase segregation and pave the way for numerical methods addressing partial segregation in multi-species or multi-phase systems.
Abstract
We study partially segregated elliptic systems through the use of penalized energy functionals. These systems arise from the minimization of Gross-Pitaevskii-type energies that capture the behavior of multi-component ultracold gas mixtures and other systems involving multiple interacting fluid or gas species. In the case when the domain is planar, i.e., in $\mathbb{R}^2$, our main result is the Gamma convergence of penalized energy to the constrained Dirichlet energy with strict segregation. The proof combines lower semicontinuity arguments with a recovery sequence construction based on geometric decompositions near interfaces and triple junctions. This establishes a rigorous variational link between the penalized and constrained formulations.
