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1  Introduction ................................................. 5
2  Preliminaries ............................................... 13
   2.1  Sobolev spaces ......................................... 13
   2.2  Invertibility of Sobolev mappings ...................... 14
   2.3  The Hardy space  1(  ) ................................. 15
   2.4  Jacobians of Sobolev mappings .......................... 17
   2.5  VMO(  ) and BMO(  ) ..................................... 18
   2.6  The Cauchy transform and the Beurling transform ........ 20
   2.7  Commutators ............................................ 21
   2.8  An equivalent norm in BMO(  ) ........................... 22
   2.9  Banach spaces .......................................... 24
3  The Jacobian Equation with Radial Data ...................... 26
   3.1  Radial stretchings as solutions ........................ 26
   3.2  Generalized radially symmetric solutions ............... 31
4  Energy-Minimal Solutions and Lagrange Multipliers ........... 35
   4.1  Energy-minimal solutions ............................... 35
   4.2  Lagrange multipliers ................................... 37
   4.3  Operator theoretical treatment of Lagrange
        multipliers ............................................ 38
5  On the Existence of Lagrange Multipliers .................... 39
   5.1  The norm ||•|| bmos and Lagrange multipliers ........... 39
   5.2  Lagrange multipliers in VMOS(  ) ....................... 40
   5.3  Characterizations of the norms ||•||BMOS and ||•||H1S ... 41
   5.4  Connection to commutators ............................. 42
6  On the Class  L2S ........................................... 44
   6.1  Topological properties of {|S|2 - ||2 :  ϵ  L2S} ..... 44
   6.2  Extreme points of  H1S ................................. 45
   6.3  The duality mapping D:  VMOS →  H1S ..................... 45
7  Local Study of Energy-Minimal Solutions and Lagrange
   Multipliers ................................................. 48
   7.1  Lagrange multipliers in a bounded domain ............... 48
   7.2  Smooth, compactly supported Lagrange multipliers ....... 51
8  Behavior of Solutions in Domains Where the Jacobian
   Vanishes .................................................... 54
   8.1  The Hopf-Laplace equation .............................. 54
   8.2  Harmonicity of solutions ............................... 56
   8.3  Solution of a problem of Lou, Yang and Song ............ 58
   References .................................................. 62 |