<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="static/style.xsl"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-09-22T11:32:48Z</responseDate><request verb="GetRecord" identifier="oai:repository.rice.edu:1911/115193" metadataPrefix="dim">https://repository.rice.edu/server/oai/request</request><GetRecord><record><header><identifier>oai:repository.rice.edu:1911/115193</identifier><datestamp>2026-09-14T18:49:45Z</datestamp><setSpec>com_1911_8299</setSpec><setSpec>col_1911_13110</setSpec></header><metadata><dim:dim xmlns:dim="http://www.dspace.org/xmlns/dspace/dim" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:doc="http://www.lyncode.com/xoai" xsi:schemaLocation="http://www.dspace.org/xmlns/dspace/dim http://www.dspace.org/schema/dim.xsd">
   <dim:field mdschema="dc" element="contributor" qualifier="advisor">Hardt, Robert M</dim:field>
   <dim:field mdschema="dc" element="creator">Valfells, Asgeir</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="accessioned">2023-08-09T19:25:00Z</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="available">2023-08-09T19:25:00Z</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="created">2023-05</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="issued">2023-04-21</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="submitted">May 2023</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="updated">2023-08-09T19:25:01Z</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="citation">Valfells, Asgeir. &amp;quot;Local Criteria in Polyhedral Minimizing Problems.&amp;quot; (2023) Diss.,  Rice University.  https://hdl.handle.net/1911/115193</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="uri">https://hdl.handle.net/1911/115193</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="abstract">This thesis will discuss two polyhedral minimizing problems and the necessary local criteria we find any such minimizers must have. We will also briefly discuss an extension of a third minimizing problem to higher dimension.&#xd;
&#xd;
 The first result we present classifies the three-dimensional piecewise linear cones in $\mathbb{R}^4$ that are mass minimizing w.r.t. Lipschitz maps in the sense of Almgren&amp;apos;s $M(0,\delta)$ sets as in Taylor&amp;apos;s classification of two-dimensional soap film singularities. There are three that arise naturally by taking products of $\mathbb{R}$ with lower dimensional cases and earlier literature has demonstrated the existence of two with 0-dimensional singularities. We classify all possible candidates and demonstrate that there are no p.l. minimizers outside these five.&#xd;
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 The second result we present is an assortment of criteria for edge-length minimizing polyhedrons. The aim is to get closer to answering a 1957 conjecture by Zdzislaw Melzak, that the unit volume polyhedron with least edge length was a triangular right prism, with edge length $2^{2/3}3^{11/6}\approx 11.896$. We present a variety of variational arguments to restrict the class of minimizing candidates.</dim:field>
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   <dim:field mdschema="dc" element="language" qualifier="iso">eng</dim:field>
   <dim:field mdschema="dc" element="rights">Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.</dim:field>
   <dim:field mdschema="dc" element="subject">Geometric Measure Theory</dim:field>
   <dim:field mdschema="dc" element="subject">Minimizing Cones</dim:field>
   <dim:field mdschema="dc" element="subject">Minimal Surfaces</dim:field>
   <dim:field mdschema="dc" element="subject">Polyhedrons</dim:field>
   <dim:field mdschema="dc" element="title">Local Criteria in Polyhedral Minimizing Problems</dim:field>
   <dim:field mdschema="dc" element="type">Thesis</dim:field>
   <dim:field mdschema="dc" element="type" qualifier="material">Text</dim:field>
   <dim:field mdschema="thesis" element="degree" qualifier="department">Mathematics</dim:field>
   <dim:field mdschema="thesis" element="degree" qualifier="discipline">Natural Sciences</dim:field>
   <dim:field mdschema="thesis" element="degree" qualifier="grantor">Rice University</dim:field>
   <dim:field mdschema="thesis" element="degree" qualifier="level">Doctoral</dim:field>
   <dim:field mdschema="thesis" element="degree" qualifier="name">Doctor of Philosophy</dim:field>
   <dim:field mdschema="others" element="access-status">open.access</dim:field>
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