Lower bound for energies of harmonic tangent unit-vector fields on convex polyhedra

نویسندگان

  • A Majumdar
  • JM Robbins
چکیده

We derive a lower bound for energies of harmonic maps of convex polyhedra in R 3 to the unit sphere S, with tangent boundary conditions on the faces. We also establish that C maps, satisfying tangent boundary conditions, are dense with respect to the Sobolev norm, in the space of continuous tangent maps of finite energy. Mathematics Subject Classifications (2000). 58E20, 35J55.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

S-valued harmonic maps on polyhedra with tangent boundary conditions

A unit-vector field n : P → S2 on a convex polyhedron P ⊂ R3 satisfies tangent boundary conditions if, on each face of P , n takes values tangent to that face. Tangent unit-vector fields are necessarily discontinuous at the vertices of P . We consider fields which are continuous elsewhere. We derive a lower bound E P (h) for the infimum Dirichlet energy Einf P (h) for such tangent unit-vector f...

متن کامل

Classification of unit-vector fields in convex polyhedra with tangent boundary conditions

A unit-vector field n on a convex three-dimensional polyhedron P̄ is tangent if, on the faces of P̄ , n is tangent to the faces. A homotopy classification of tangent unit-vector fields continuous away from the vertices of P̄ is given. The classification is determined by certain invariants, namely edge orientations (values of n on the edges of P̄ ), kink numbers (relative winding numbers of n betwee...

متن کامل

Lower Bounds on Stabbing Lines in 3-space

A stabbing line for a set of convex polyhedra is extremal if it passes through four edges and is tangent to the polyhedra containing those edges. In this paper we present three constructions of convex polyhedra with many extremal lines. The rst construction shows (n 2) extremal stabbing lines constrained to meet two skew lines. The second shows (n 4) extremal lines which are tangent to two poly...

متن کامل

Liquid crystals and harmonic maps in polyhedral domains

Unit-vector fields n on a convex polyhedron P subject to tangent boundary conditions provide a simple model of nematic liquid crystals in prototype bistable displays. The equilibrium and metastable configurations correspond to minimisers and local minimisers of the Dirichlet energy, and may be regarded as S-valued harmonic maps on P . We consider unit-vector fields which are continuous away fro...

متن کامل

Optimality conditions for Pareto efficiency and proper ideal point in set-valued nonsmooth vector optimization using contingent cone

In this paper, we first present a new important property for Bouligand tangent cone (contingent cone) of a star-shaped set. We then establish optimality conditions for Pareto minima and proper ideal efficiencies in nonsmooth vector optimization problems by means of Bouligand tangent cone of image set, where the objective is generalized cone convex set-valued map, in general real normed spaces.

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2004