Deformations of Bi-conformal Energy and a New Characterization of Quasiconformality
Year of publication
2020
Authors
Iwaniec, Tadeusz; Onninen, Jani; Zhu, Zheng
Abstract
The concept of hyperelastic deformations of bi-conformal energy is developed as an extension of quasiconformality. These deformations are homeomorphisms h : X onto −→ Y between domains X, Y ⊂ Rn of the Sobolev class W 1,n loc (X, Y) whose inverse f def == h−1 : Y onto −→ X also belongs to W 1,n loc (Y, X). Thus the paper opens new topics in Geometric Function Theory (GFT) with connections to mathematical models of Nonlinear Elasticity (NE). In seeking differences and similarities with quasiconformal mappings we examine closely the modulus of continuity of deformations of bi-conformal energy. This leads us to a new characterization of quasiconformality. Specifically, it is observed that quasiconformal mappings behave locally at every point like radial stretchings; if a quasiconformal map h admits a function φ as its optimal modulus of continuity at a point x◦ , then f = h−1 admits the inverse function ψ = φ−1 as its modulus of continuity at y◦ = h(x◦). That is to say, a poor (possibly harmful) continuity of h at a given point x◦ is always compensated by a better continuity of f at y◦ , and vice versa. Such a gain/loss property, seemingly overlooked by many authors, is actually characteristic of quasiconformal mappings. It turns out that the elastic deformations of bi-conformal energy are very different in this respect. Unexpectedly, such a map may have the same optimal modulus of continuity as its inverse deformation. In line with Hooke’s Law, when trying to restore the original shape of the body (by the inverse transformation), the modulus of continuity may neither be improved nor become worse. However, examples to confirm this phenomenon are far from being obvious; indeed, elaborate computations are on the way. We eventually hope that our examples will gain an interest in the materials science, particularly in mathematical models of hyperelasticity.
Show moreOrganizations and authors
Publication type
Publication format
Article
Parent publication type
Journal
Article type
Original article
Audience
ScientificPeer-reviewed
Peer-ReviewedMINEDU's publication type classification code
A1 Journal article (refereed), original researchPublication channel information
Publisher
Volume
236
Issue
3
Pages
1709-1737
ISSN
Publication forum
Publication forum level
3
Open access
Open access in the publisher’s service
No
Self-archived
No
Other information
Fields of science
Mathematics
Keywords
[object Object],[object Object]
Publication country
Germany
Internationality of the publisher
International
Language
English
International co-publication
Yes
Co-publication with a company
No
DOI
10.1007/s00205-020-01502-w
The publication is included in the Ministry of Education and Culture’s Publication data collection
Yes