Permanent URL to this publication: http://dx.doi.org/10.5167/uzh21813
De Lellis, C; Grisanti, C; Tilli, P (2004). Regular selections for multiplevalued functions. Annali di Matematica Pura ed Applicata. Series IV, 183(1):7995.

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Abstract
Given a multiplevalued function f, we deal with the problem of selecting its single valued branches. This problem can be stated in a rather abstract setting considering a metric space E and a finite group G of isometries of E. Given a function f which takes values in the equivalence classes of E/G, the problem consists in finding a map g with the same domain as f and taking values in E, such that at every point t the equivalence class of g(t) coincides with f(t). If the domain of f is an interval, we show the existence of a function g with these properties which, moreover, has the same modulus of continuity of f. In the particular case where E is the product of Q copies of ℝ n and G is the group of permutations of Q elements, it is possible to introduce a notion of differentiability for multiple valued functions. In this case, we prove that the function g can be constructed in such a way to preserve C k,α regularity. Some related problems are also discussed.
Item Type:  Journal Article, refereed, original work 

Communities & Collections:  07 Faculty of Science > Institute of Mathematics 
DDC:  510 Mathematics 
Uncontrolled Keywords:  modulus of continuity; differentiability 
Language:  English 
Date:  2004 
Deposited On:  17 Sep 2010 07:26 
Last Modified:  22 Jan 2014 03:28 
Publisher:  Springer 
ISSN:  03733114 
Additional Information:  The original publication is available at www.springerlink.com 
Publisher DOI:  10.1007/s1023100300815 
Related URLs:  http://www.ams.org/mathscinetgetitem?mr=2044333 
Citations:  Web of Science®. Times Cited: 6 Google Scholar™ Scopus®. Citation Count: 5 
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