{ "id": "2112.03453", "version": "v2", "published": "2021-12-07T02:29:45.000Z", "updated": "2022-09-28T23:26:22.000Z", "title": "Existence of minimizers and convergence of critical points for a new Landau-de Gennes energy functional in nematic liquid crystals", "authors": [ "Zhewen Feng", "Min-Chun Hong" ], "comment": "Revised vision. To appear in Calculus of Variations and Partial Differential Equations. arXiv admin note: text overlap with arXiv:2007.11144", "categories": [ "math.AP" ], "abstract": "The Landau-de Gennes energy in nematic liquid crystals depends on four elastic constants $L_1$, $L_2$, $L_3$, $L_4$. In the case of $L_4\\neq 0$, Ball and Majumdar (Mol. Cryst. Liq. Cryst., 2010) found an example that the original Landau-de Gennes energy functional in physics does not satisfy a coercivity condition, which causes a problem in mathematics to establish existence of energy minimizers. At first, we introduce a new Landau-de Gennes energy density with $L_4\\neq 0$, which is equivalent to the original Landau-de Gennes density for uniaxial tensors and satisfies the coercivity condition for all $Q$-tensors. Secondly, we prove that solutions of the Landau-de Gennes system can approach a solution of the $Q$-tensor Oseen-Frank system without using energy minimizers. Thirdly, we develop a new approach to generalize the Nguyen and Zarnescu (Calc. Var. PDEs, 2013) convergence result to the case of non-zero elastic constants $L_2$, $L_3$, $L_4$.", "revisions": [ { "version": "v2", "updated": "2022-09-28T23:26:22.000Z" } ], "analyses": { "subjects": [ "35J20", "35Q35", "76A15" ], "keywords": [ "nematic liquid crystals", "critical points", "convergence", "original landau-de gennes energy functional", "landau-de gennes energy density" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }