@article{PMIHES_2004__99__1_0,
     author = {Bourgain, Jean and Brezis, Haim and Mironescu, Petru},
     title = {$H^{1/2}$ maps with values into the circle : minimal connections, lifting, and the {Ginzburg-Landau} equation},
     journal = {Publications Math\'ematiques de l'IH\'ES},
     pages = {1--115},
     publisher = {Springer},
     volume = {99},
     year = {2004},
     doi = {10.1007/s10240-004-0019-5},
     zbl = {1051.49030},
     language = {en},
     url = {http://www.numdam.org/articles/10.1007/s10240-004-0019-5/}
}