SPLITTING LOOPS AND NECKLACES: VARIANTS OF THE SQUARE PEG PROBLEM

Toeplitz conjectured that any simple planar loop inscribes a square. Here we prove variants of Toeplitz’s square peg problem. We prove Hadwiger’s 1971 conjecture that any simple loop in $3$-space inscribes a parallelogram. We show that any simple planar loop inscribes sufficiently many rectangles th...

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Main Authors: JAI ASLAM, SHUJIAN CHEN, FLORIAN FRICK, SAM SALOFF-COSTE, LINUS SETIABRATA, HUGH THOMAS
Format: Article
Language:English
Published: Cambridge University Press 2020-01-01
Series:Forum of Mathematics, Sigma
Subjects:
Online Access:https://www.cambridge.org/core/product/identifier/S2050509419000513/type/journal_article
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author JAI ASLAM
SHUJIAN CHEN
FLORIAN FRICK
SAM SALOFF-COSTE
LINUS SETIABRATA
HUGH THOMAS
author_facet JAI ASLAM
SHUJIAN CHEN
FLORIAN FRICK
SAM SALOFF-COSTE
LINUS SETIABRATA
HUGH THOMAS
author_sort JAI ASLAM
collection DOAJ
description Toeplitz conjectured that any simple planar loop inscribes a square. Here we prove variants of Toeplitz’s square peg problem. We prove Hadwiger’s 1971 conjecture that any simple loop in $3$-space inscribes a parallelogram. We show that any simple planar loop inscribes sufficiently many rectangles that their vertices are dense in the loop. If the loop is rectifiable, there is a rectangle that cuts the loop into four pieces which can be rearranged to form two loops of equal length. (The previous two results are independently due to Schwartz.) A rectifiable loop in $d$-space can be cut into $(r-1)(d+1)+1$ pieces that can be rearranged by translations to form $r$ loops of equal length. We relate our results to fair divisions of necklaces in the sense of Alon and to Tverberg-type results. This provides a new approach and a common framework to obtain inscribability results for the class of all continuous curves.
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spelling doaj.art-4433ce7df8e94150982457b1a37db65c2023-03-09T12:34:47ZengCambridge University PressForum of Mathematics, Sigma2050-50942020-01-01810.1017/fms.2019.51SPLITTING LOOPS AND NECKLACES: VARIANTS OF THE SQUARE PEG PROBLEMJAI ASLAM0SHUJIAN CHEN1FLORIAN FRICK2SAM SALOFF-COSTE3LINUS SETIABRATA4HUGH THOMAS5Department of Mathematics, North Carolina State University, Raleigh, NC27695, USA;Department of Mathematics, Brandeis University, Waltham, MA02453, USA;Department of Mathematics Sciences, Carnegie Mellon University, Pittsburgh, PA15213, USA;Department of Mathematics, Cornell University, Ithaca, NY14853, USA; ,Department of Mathematics, Cornell University, Ithaca, NY14853, USA; ,Math. Dept., Université du Québec á Montréal, QuebecH2X 3Y7, Canada;Toeplitz conjectured that any simple planar loop inscribes a square. Here we prove variants of Toeplitz’s square peg problem. We prove Hadwiger’s 1971 conjecture that any simple loop in $3$-space inscribes a parallelogram. We show that any simple planar loop inscribes sufficiently many rectangles that their vertices are dense in the loop. If the loop is rectifiable, there is a rectangle that cuts the loop into four pieces which can be rearranged to form two loops of equal length. (The previous two results are independently due to Schwartz.) A rectifiable loop in $d$-space can be cut into $(r-1)(d+1)+1$ pieces that can be rearranged by translations to form $r$ loops of equal length. We relate our results to fair divisions of necklaces in the sense of Alon and to Tverberg-type results. This provides a new approach and a common framework to obtain inscribability results for the class of all continuous curves.https://www.cambridge.org/core/product/identifier/S2050509419000513/type/journal_article53A0451M04
spellingShingle JAI ASLAM
SHUJIAN CHEN
FLORIAN FRICK
SAM SALOFF-COSTE
LINUS SETIABRATA
HUGH THOMAS
SPLITTING LOOPS AND NECKLACES: VARIANTS OF THE SQUARE PEG PROBLEM
Forum of Mathematics, Sigma
53A04
51M04
title SPLITTING LOOPS AND NECKLACES: VARIANTS OF THE SQUARE PEG PROBLEM
title_full SPLITTING LOOPS AND NECKLACES: VARIANTS OF THE SQUARE PEG PROBLEM
title_fullStr SPLITTING LOOPS AND NECKLACES: VARIANTS OF THE SQUARE PEG PROBLEM
title_full_unstemmed SPLITTING LOOPS AND NECKLACES: VARIANTS OF THE SQUARE PEG PROBLEM
title_short SPLITTING LOOPS AND NECKLACES: VARIANTS OF THE SQUARE PEG PROBLEM
title_sort splitting loops and necklaces variants of the square peg problem
topic 53A04
51M04
url https://www.cambridge.org/core/product/identifier/S2050509419000513/type/journal_article
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