<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=Windows-1252">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style><![endif]--><style><!--
/* Font Definitions */
@font-face
{font-family:Helvetica;
panose-1:0 0 0 0 0 0 0 0 0 0;}
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Aptos;
panose-1:2 11 0 4 2 2 2 2 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
font-size:10.0pt;
font-family:"Calibri",sans-serif;}
span.apple-converted-space
{mso-style-name:apple-converted-space;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;
mso-ligatures:none;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="blue" vlink="purple" style="word-wrap:break-word">
<div class="WordSection1">
<div id="mail-editor-reference-message-container">
<div>
<div>
<div id="mail-editor-reference-message-container">
<div>
<div>
<div id="mail-editor-reference-message-container">
<div>
<div>
<div id="mail-editor-reference-message-container">
<div>
<div>
<div id="mail-editor-reference-message-container">
<div>
<div>
<div id="mail-editor-reference-message-container">
<div>
<div>
<div id="mail-editor-reference-message-container">
<div>
<div>
<div id="mail-editor-reference-message-container">
<div>
<div>
<div id="mail-editor-reference-message-container">
<div>
<div>
<div id="mail-editor-reference-message-container">
<div>
<div>
<div id="mail-editor-reference-message-container">
<div>
<div>
<div id="mail-editor-reference-message-container">
<div>
<div>
<div id="mail-editor-reference-message-container">
<div>
<div>
<div id="mail-editor-reference-message-container">
<div>
<div>
<div id="mail-editor-reference-message-container">
<div>
<div>
<div id="mail-editor-reference-message-container">
<div>
<div>
<div id="mail-editor-reference-message-container">
<div>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><i><span style="font-size:12.0pt;font-family:Helvetica;color:#8B0102"> </span></i><o:p></o:p></p>
<p class="MsoNormal"><i><span style="font-size:12.0pt;font-family:Helvetica;color:#8B0102">UNIVERSITY OF CHICAGO</span></i><o:p></o:p></p>
<p class="MsoNormal"><i><span style="font-size:12.0pt;font-family:Helvetica;color:#8B0102">COMPUTER SCIENCE DEPARTMENT</span></i><o:p></o:p></p>
<p class="MsoNormal"><i><span style="font-size:12.0pt;font-family:Helvetica;color:#8B0102">PRESENTS</span></i><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt;color:black"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt;color:black"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt;color:black"> </span><o:p></o:p></p>
<p class="MsoNormal"><b><span style="font-size:12.0pt;font-family:Helvetica">Haotian Jiang, PhD</span></b><o:p></o:p></p>
<p class="MsoNormal"><b><span style="font-size:12.0pt;font-family:"Aptos",sans-serif">Microsoft Research/UChicago</span></b><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:Helvetica;color:black"> </span></b><b><span style="font-size:11.0pt;font-family:Helvetica"><img width="240" height="244" style="width:2.5in;height:2.5416in" id="Picture_x0020_3" src="cid:image001.png@01DA64D5.B8323240" alt="A person wearing glasses and smiling
Description automatically generated"></span></b><o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal"><b><span style="font-size:12.0pt;color:black;background:yellow">Tuesday, February 27, 2024, at 3:30pm</span></b><o:p></o:p></p>
<p class="MsoNormal"><b><span style="font-size:12.0pt">Room: Ryerson 251</span></b><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><b><i><span style="font-size:12.0pt;font-family:"Aptos",sans-serif">T<span style="color:#212121">itle:</span></span></i></b><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:#212121">
</span><span style="font-size:12.0pt">Sparse Submodular Function Minimization</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:#212121"> </span><o:p></o:p></p>
<p class="MsoNormal"><b><i><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:#212121">Abstract:</span></i></b><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:#212121">
</span><span style="font-size:12.0pt;color:black;background:white">We discuss the problem of minimizing a submodular function (defined on an n-element ground set) that is guaranteed to have a k-sparse minimizer. I will present a weakly polynomial time parallel
algorithm with \poly(k)-depth and a strongly polynomial time algorithm that makes n \poly(k) queries to an evaluation oracle. When k is small, our algorithms have sub-linear parallel depth or sub-quadratic evaluation oracle query complexities. All previous
algorithms for this problem have at least linear parallel depth and make at least a quadratic number of queries. In contrast to state-of-the-art weakly- and strongly-polynomial time algorithms for SFM that all apply cutting plane methods, our algorithms use
first-order methods. We introduce what we call sparse dual certificates, which encode information on the sparse minimizers, and our algorithms provide new algorithmic tools for allowing first-order optimization methods to efficiently compute them.
</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black;background:white">This talk is based on joint work with Andrei Graur and Aaron Sidford, both from Stanford University.</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><b><i><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:#212121">Bio</span></i></b><b><i><span style="font-size:12.0pt;font-family:"Aptos",sans-serif">:
</span></i></b><span style="font-size:12.0pt;letter-spacing:-.1pt">I’m <span style="color:#202020">
currently a Postdoctoral Researcher at Microsoft Research, Redmond. In December 2022,
</span>I<span style="color:#202020"> obtained his PhD from the Paul G. Allen School of Computer Science & Engineering at the University of Washington under the supervision of Yin Tat Lee.
</span>I am<span style="color:#202020"> broadly interested in theoretical computer science and applied mathematics.
</span>My<span style="color:#202020"> primary area of expertise is the design and analysis of algorithms for continuous and discrete optimization problems, and algorithm design through the lens of discrepancy theory.</span></span><o:p></o:p></p>
<p><span style="color:black"> </span><o:p></o:p></p>
<p style="margin-bottom:12.0pt"><b><span style="font-size:12.0pt;font-family:Helvetica;color:black">Host:<span class="apple-converted-space"> A</span></span></b><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:Helvetica">lexander
Razborov</span></b></span><o:p></o:p></p>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</body>
</html>