Let distK\dist_K be the distance from a compact set K⊂Mm×nK\subset\mathbb{M}^{m\times n} in the space of m×nm\times n matrices. This note determines the set Mp⊂Mm×nM_p\subset \mathbb{M}^{m\times n} of zeros of the polyconvex hull of distKp\dist_K^p where 1≤p<∞1\leq p<\infty. It is shown that the set-valued map p↦Mpp\mapsto M_p is constant on the intervals [1,2),…,[q−1,q),[q,∞)[1,2),\dots,[q-1,q),[q,\infty) where q:=min⁡{m,n}q:=\min\{ m, n\}, while at p=1,…,qp=1,\dots,q the set MpM_p generally jumps down discontinuously. The values MsM_s, s=1,…,qs= 1,\dots,q, at the beginnings of intervals of constancy are characterized as ss-polyconvex hulls PsK\P^sK of KK to be defined below, where P1K\P^1K is the convex hull and PqK\P^qK the standard polyconvex hull. As an illustration, PsSO(n)\P^sSO(n) are evaluated for all ss if 1≤n≤41\leq n\leq 4, and for nn arbitrary if n≥s>n/2n\geq s>n/2 and/or s=1s=1. In the remaining cases only bounds are obtained.

Contact details are reproduced from the original publication and may be historical.

Miroslav Šilhavý

Dip. di Matematica, Università di Pisa, Largo Bruno Pontecorvo 5, 56127 Pisa, Italy
Permanent Address: Mathematical Institute, Academy of Sciences, Žitná 25, 115 67 Prague 1, Czech Republic

silhavy@math.cas.cz
  1. J. M. Ball: Convexity conditions and existence theorems in nonlinear elasticity, Arch. Ration. Mech. Anal. 63 (1977) 337–403.https://doi.org/10.1007/BF00279992Google Scholar
  2. J. M. Ball: Sets of gradients with no rank-one connections, J. Math. Pures Appl. 69 (1990) 241–259.Google Scholar
  3. J. M. Ball, J. C. Currie, P. J. Olver: Null Lagrangians, weak continuity, and variational problems of arbitrary order, J. Funct. Anal. 41 (1981) 135–174.https://doi.org/10.1016/0022-1236(81)90085-9Google Scholar
  4. B. Dacorogna: Direct Methods in the Calculus of Variations, Springer, Berlin (1989).https://doi.org/10.1007/978-3-642-51440-1Google Scholar
  5. B. Dacorogna, P. Marcellini: Implicit Partial Differential Equations, Birkhäuser, Boston (1999).https://doi.org/10.1007/978-1-4612-1562-2Google Scholar
  6. W. Gangbo: On the continuity of the polyconvex, quasiconvex and rank-one-convex envelopes with respect to growth condition, Proc. R. Soc. Edinb., Sect. A 123 (1993) 707–729.https://doi.org/10.1017/S0308210500030924Google Scholar
  7. T. Iwaniec, A. Lutoborski: Integral estimates for null Lagrangians, Arch. Ration. Mech. Anal. 125 (1993) 25–79.https://doi.org/10.1007/BF00411477Google Scholar
  8. T. Iwaniec, A. Lutoborski: Polyconvex functionals for nearly conformal deformations, SIAM J. Math. Anal. 27 (1996) 609–619.https://doi.org/10.1137/0527033Google Scholar
  9. D. Kinderlehrer: Remarks about equilibrium configurations of crystals, in: Material Instabilities in Continuum Mechanics, J. M. Ball (ed.), Oxford Univeristy Press, Oxford (1988) 217–241.Google Scholar
  10. A. W. Marshall, I. Olkin: Inequalities: Theory of Majorization and its Applications, Academic Press, New York (1979).Google Scholar
  11. J. Matoušek: On directional convexity, Discrete Comput. Geom. 25 (2001) 389–405.https://doi.org/10.1007/s004540010069Google Scholar
  12. C. B. Morrey Jr.: Multiple Integrals in the Calculus of Variations, Springer, Berlin (1966).https://doi.org/10.1007/978-3-540-69952-1Google Scholar
  13. S. Müller: Variational models for microstructure and phase transitions, in: Calculus of Variations and Geometric Evolution Problems (Cetraro, 1996), Lecture Notes in Math. 1713, Springer, Berlin (1999) 85–210.https://doi.org/10.1007/BFb0092670Google Scholar
  14. P. Rosakis: Characterization of convex isotropic functions, J. Elasticity 49 (1997) 257–267.https://doi.org/10.1023/A:1007468902439Google Scholar
  15. M. Šilhavý: The Mechanics and Thermodynamics of Continuous Media, Springer, Berlin (1997).https://doi.org/10.1007/978-3-662-03389-0Google Scholar
  16. M. Šilhavý: Rank 1 convex hulls of isotropic functions in dimension 2 by 2, Math. Bohem. 126 (2001) 521–529.https://doi.org/10.21136/MB.2001.134029Google Scholar
  17. M. Šilhavý: Monotonicity of rotationally invariant convex and rank 1 convex functions, Proc. R. Soc. Edinb., Sect. A, Math. 132 (2002) 419–435.https://doi.org/10.1017/S0308210500001712Google Scholar
  18. M. Šilhavý: An O(n) invariant quasiconvex function that is not polyconvex, Preprint No. 150, Mathematical Institute AS ČR (2002).Google Scholar
  19. M. Šilhavý: Liquefaction points and the occurrence of effective liquid response in nonelliptic solids, in preparation (2003).Google Scholar
  20. B. Yan: On rank-one convex and polyconvex conformal energy functions with slow growth, Proc. R. Soc. Edinb., Sect. A, Math. 127 (1997) 651–663.https://doi.org/10.1017/S0308210500029954Google Scholar
  21. K. Zhang: Quasiconvex functions, SO(n) and two elastic wells, Ann. Inst. H. Poincaré, Anal. Non Linéaire 14 (1997) 759–785.https://doi.org/10.1016/s0294-1449(97)80132-1Google Scholar

M. Šilhavý. “Zeros of the Polyconvex Hull of Powers of the Distance and s-Polyconvexity.” Journal of Convex Analysis 14 (2007), No. 2, 319–344. https://doi.org/10.68381/jca14022