{ "id": "1907.04726", "version": "v1", "published": "2019-07-10T13:52:30.000Z", "updated": "2019-07-10T13:52:30.000Z", "title": "Characterization of the critical points for the free energy of a Cosserat problem", "authors": [ "Petre Birtea", "Ioan Casu", "Dan Comanescu" ], "categories": [ "math-ph", "math.MP", "math.OC" ], "abstract": "Using the embedded gradient vector field method we explicitly compute the list of critical points of the free energy for a Cosserat body model. We also formulate necessary and sufficient conditions for critical points in the abstract case of the special orthogonal group $SO(n)$. Each critical point is then characterized using an explicit formula for the Hessian operator of a cost function defined on the orthogonal group. We also give a positive answer to an open question posed in L. Borisov, A. Fischle, P. Neff, \"Optimality of the relaxed polar factors by a characterization of the set of real square roots of real symmetric matrices\", ZAMM (2019), namely if all local minima of the optimization problem are global minima. We point out a few examples with physical relevance, in contrast to some theoretical (mathematical) situations that do not hold such a relevance.", "revisions": [ { "version": "v1", "updated": "2019-07-10T13:52:30.000Z" } ], "analyses": { "subjects": [ "74A30", "74A60", "74G05", "74G65", "74N15", "53B21" ], "keywords": [ "critical point", "free energy", "cosserat problem", "characterization", "embedded gradient vector field method" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }