@article{cf7f523ffd494d68aa6f512f84e5890a,
title = "Sharp Finiteness Principles For Lipschitz Selections",
abstract = "Let (M, ρ) be a metric space and let Y be a Banach space. Given a positive integer m, let F be a set-valued mapping from M into the family of all compact convex subsets of Y of dimension at most m. In this paper we prove a finiteness principle for the existence of a Lipschitz selection of F with the sharp value of the finiteness constant.",
keywords = "Helly{\textquoteright}s theorem, Lipschitz selection, Metric tree, Nagata dimension, Set-valued mapping, Steiner-type point, Whitney partition",
author = "Charles Fefferman and Pavel Shvartsman",
note = "Funding Information: We are grateful to Alexander Brudnyi, Arie Israel, Bo{\textquoteright}az Klartag, Garving (Kevin) Luli and the participants of the 10th Whitney Problems Conference, Williamsburg, VA, for valuable conversations. We thank the referee for very careful reading and numerous suggestions, which led to improvements in our exposition. We are grateful also to the College of William and Mary, Williamsburg, VA, USA, the American Institute of Mathematics, San Jose, CA, USA, the Fields Institute, Toronto, Canada, the University of Arkansas, AR, USA, the Banff International Research Station, Banff, Canada, the Centre International de Rencontres Math{\'e}matiques (CIRM), Luminy, Marseille, France, and the Technion, Haifa, Israel, for hosting and supporting workshops on the topic of this paper and closely related problems. Finally, we thank the US-Israel Binational Science Foundation, the US National Science Foundation, the Office of Naval Research and the Air Force Office of Scientific Research for generous support. Funding Information: We are grateful to Alexander Brudnyi, Arie Israel, Bo?az Klartag, Garving (Kevin) Luli and the participants of the 10th Whitney Problems Conference, Williamsburg, VA, for valuable conversations. We thank the referee for very careful reading and numerous suggestions, which led to improvements in our exposition. We are grateful also to the College of William and Mary, Williamsburg, VA, USA, the American Institute of Mathematics, San Jose, CA, USA, the Fields Institute, Toronto, Canada, the University of Arkansas, AR, USA, the Banff International Research Station, Banff, Canada, the Centre International de Rencontres Math?matiques (CIRM), Luminy, Marseille, France, and the Technion, Haifa, Israel, for hosting and supporting workshops on the topic of this paper and closely related problems. Finally, we thank the US-Israel Binational Science Foundation, the US National Science Foundation, the Office of Naval Research and the Air Force Office of Scientific Research for generous support. This research was supported by Grant No 2014055 from the United States-Israel Binational Science Foundation (BSF). Charles Fefferman was also supported in part by NSF Grant DMS- 1265524 and AFOSR Grant FA9550-12-1-0425. Funding Information: This research was supported by Grant No 2014055 from the United States-Israel Binational Science Foundation (BSF). Charles Fefferman was also supported in part by NSF Grant DMS-1265524 and AFOSR Grant FA9550-12-1-0425. Keywords and phrases: Set-valued mapping, Lipschitz selection, Metric tree, Helly{\textquoteright}s theorem, Nagata dimension, Whitney partition, Steiner-type point Mathematics Subject Classification: 46E35 Publisher Copyright: {\textcopyright} 2018, Springer Nature Switzerland AG.",
year = "2018",
month = dec,
day = "1",
doi = "10.1007/s00039-018-0467-6",
language = "English (US)",
volume = "28",
pages = "1641--1705",
journal = "Geometric and Functional Analysis",
issn = "1016-443X",
publisher = "Birkhauser Verlag Basel",
number = "6",
}