English

Q-valued functions revisited

Analysis of PDEs 2011-03-18 v4

Abstract

In this note we revisit Almgren's theory of Q-valued functions, that are functions taking values in the space of unordered Q-tuples of points in R^n. In particular: 1) we give shorter versions of Almgren's proofs of the existence of Dir-minimizing Q-valued functions, of their Hoelder regularity and of the dimension estimate of their singular set; 2) we propose an alternative intrinsic approach to these results, not relying on Almgren's biLipschitz embedding; 3) we improve upon the estimate of the singular set of planar Dir-minimizing functions by showing that it consists of isolated points.

Keywords

Cite

@article{arxiv.0803.0060,
  title  = {Q-valued functions revisited},
  author = {Camillo De Lellis and Emanuele Nunzio Spadaro},
  journal= {arXiv preprint arXiv:0803.0060},
  year   = {2011}
}

Comments

84 pages, 3 figures; changes: few typos corrected, reformatted for submission

R2 v1 2026-06-21T10:17:25.952Z