<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE article  PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "http://dtd.nlm.nih.gov/publishing/3.0/journalpublishing3.dtd"><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" dtd-version="3.0" xml:lang="en" article-type="research article"><front><journal-meta><journal-id journal-id-type="publisher-id">AM</journal-id><journal-title-group><journal-title>Applied Mathematics</journal-title></journal-title-group><issn pub-type="epub">2152-7385</issn><publisher><publisher-name>Scientific Research Publishing</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.4236/am.2017.83025</article-id><article-id pub-id-type="publisher-id">AM-74880</article-id><article-categories><subj-group subj-group-type="heading"><subject>Articles</subject></subj-group><subj-group subj-group-type="Discipline-v2"><subject>Physics&amp;Mathematics</subject></subj-group></article-categories><title-group><article-title>
 
 
  The Uncertainty Principle in Terms of Isoperimetric Inequalities
 
</article-title></title-group><contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Thomas</surname><given-names>Schürmann</given-names></name><xref ref-type="aff" rid="aff1"><sub>1</sub></xref><xref ref-type="corresp" rid="cor1"><sup>*</sup></xref></contrib></contrib-group><aff id="aff1"><label>1</label><addr-line>Germaniastra?e 8, Düsseldorf, Germany </addr-line></aff><author-notes><corresp id="cor1">* E-mail:<email>t.schurmann@icloud.com</email></corresp></author-notes><pub-date pub-type="epub"><day>03</day><month>03</month><year>2017</year></pub-date><volume>08</volume><issue>03</issue><fpage>307</fpage><lpage>311</lpage><history><date date-type="received"><day>14,</day>	<month>July</month>	<year>2016</year></date><date date-type="rev-recd"><day>21,</day>	<month>March</month>	<year>2017</year>	</date><date date-type="accepted"><day>24,</day>	<month>March</month>	<year>2017</year></date></history><permissions><copyright-statement>&#169; Copyright  2014 by authors and Scientific Research Publishing Inc. </copyright-statement><copyright-year>2014</copyright-year><license><license-p>This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/</license-p></license></permissions><abstract><p><html>
 <head></head>
 
  Simultaneous measurements of position and momentum are considered in 
  <em>n</em> dimensions. We find, that for a particle whose position is strictly localized in a compact domain 
  <img src="Edit_6c81c895-4f03-4d01-b343-6ecc50be729e.bmp" alt="" /> (spatial uncertainty) with non-empty boundary, the standard deviation of its momentum is sharply bounded by 
  <img src="Edit_325b68e0-32f4-44c0-8f41-2f32ae942b83.bmp" alt="" /> , while 
  <img src="Edit_f08224e9-0912-4d16-8d71-abe78ae6e972.bmp" alt="" /> is the first Dirichlet eigenvalue of the Laplacian on 
  <em>D</em>.
 
</html></p></abstract><kwd-group><kwd>Uncertainty Principle</kwd><kwd> Dirichlet Eigenvalue</kwd><kwd> Wirtinger Inequality</kwd></kwd-group></article-meta></front><body><sec id="s1"><title>Cite this paper</title><p>Sch&#252;rmann, T. (2017) The Uncertainty Principle in Terms of Isoperimetric Inequalities. Applied Mathematics, 8, 307-311. https://doi.org/10.4236/am.2017.83025</p></sec></body><back><ref-list><title>References</title><ref id="scirp.74880-ref1"><label>1</label><mixed-citation publication-type="other" xlink:type="simple">Heisenberg, W. (1927) über den anschaulichen Inhalt der quantentheoretischen Kinematik und Mechanik. Zeitschrift für Physik, 43, 172-198.  
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