A remark on the structure of the Busemann representative of a polyconvex function
Functional Analysis
2008-09-24 v1
Abstract
Let W be a polyconvex function defined on the 2 x 2 real matrices. The Busemann representative f, say, of W is the largest possible convex representative of W. Writing L for the set of affine functions on R^{5} such that a(A, det A) is less than or equal to W(A) for all 2 x 2 real matrices A, f can then be expressed as f(X) = sup {a(X): a lies in L}. This short note proves the surprising result that f is in general strictly larger than the `natural' convex representative g(X) = sup {a(X): a lies in L and a(A, det A)=W(A) for some A}.
Cite
@article{arxiv.0809.3921,
title = {A remark on the structure of the Busemann representative of a polyconvex function},
author = {J. J Bevan},
journal= {arXiv preprint arXiv:0809.3921},
year = {2008}
}