Linear Extension Numbers of n-Element Posets

Abstract We address the following natural but hitherto unstudied question: what are the possible linear extension numbers of an n-element poset? Let LE(n) denote the set of all positive integers that arise as the number of linear extensions of some n-element poset. We show that LE(n)...

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Main Authors: Kravitz, Noah, Sah, Ashwin
Other Authors: Massachusetts Institute of Technology. Department of Mathematics
Format: Article
Language:English
Published: Springer Netherlands 2021
Online Access:https://hdl.handle.net/1721.1/132100
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author Kravitz, Noah
Sah, Ashwin
author2 Massachusetts Institute of Technology. Department of Mathematics
author_facet Massachusetts Institute of Technology. Department of Mathematics
Kravitz, Noah
Sah, Ashwin
author_sort Kravitz, Noah
collection MIT
description Abstract We address the following natural but hitherto unstudied question: what are the possible linear extension numbers of an n-element poset? Let LE(n) denote the set of all positive integers that arise as the number of linear extensions of some n-element poset. We show that LE(n) skews towards the “small” end of the interval [1, n!]. More specifically, LE(n) contains all of the positive integers up to exp c n log n $\exp \left (c\frac {n}{\log n}\right )$ for some absolute constant c, and |LE(n) ∩ ((n − 1)!, n!]| < (n − 3)!. The proof of the former statement involves some intermediate number-theoretic results about the Stern-Brocot tree that are of independent interest.
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spelling mit-1721.1/1321002023-03-15T20:19:25Z Linear Extension Numbers of n-Element Posets Kravitz, Noah Sah, Ashwin Massachusetts Institute of Technology. Department of Mathematics Abstract We address the following natural but hitherto unstudied question: what are the possible linear extension numbers of an n-element poset? Let LE(n) denote the set of all positive integers that arise as the number of linear extensions of some n-element poset. We show that LE(n) skews towards the “small” end of the interval [1, n!]. More specifically, LE(n) contains all of the positive integers up to exp c n log n $\exp \left (c\frac {n}{\log n}\right )$ for some absolute constant c, and |LE(n) ∩ ((n − 1)!, n!]| < (n − 3)!. The proof of the former statement involves some intermediate number-theoretic results about the Stern-Brocot tree that are of independent interest. 2021-09-20T17:41:57Z 2021-09-20T17:41:57Z 2020-05-11 2021-04-04T03:31:39Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/132100 en https://doi.org/10.1007/s11083-020-09527-2 Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. Springer Nature B.V. application/pdf Springer Netherlands Springer Netherlands
spellingShingle Kravitz, Noah
Sah, Ashwin
Linear Extension Numbers of n-Element Posets
title Linear Extension Numbers of n-Element Posets
title_full Linear Extension Numbers of n-Element Posets
title_fullStr Linear Extension Numbers of n-Element Posets
title_full_unstemmed Linear Extension Numbers of n-Element Posets
title_short Linear Extension Numbers of n-Element Posets
title_sort linear extension numbers of n element posets
url https://hdl.handle.net/1721.1/132100
work_keys_str_mv AT kravitznoah linearextensionnumbersofnelementposets
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