<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style>
</head>
<body dir="ltr">
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Reminder: happening today, 12:30pm, JCL 390.</div>
<div id="appendonsend"></div>
<hr style="display:inline-block;width:98%" tabindex="-1">
<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Theory <theory-bounces@mailman.cs.uchicago.edu> on behalf of Adela DePavia <adepavia@uchicago.edu><br>
<b>Sent:</b> Monday, February 28, 2022 2:41 PM<br>
<b>To:</b> theory@mailman.cs.uchicago.edu <theory@mailman.cs.uchicago.edu><br>
<b>Subject:</b> [Theory] [Theory Lunch] Max Ovsiankin, Wednesday 3/2 12:30pm-1:30pm, JCL 390.</font>
<div> </div>
</div>
<style type="text/css" style="display:none">
<!--
p
{margin-top:0;
margin-bottom:0}
-->
</style>
<div dir="ltr">
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<div style="margin:0px; font-size:15px; color:rgb(32,31,30); background-color:rgb(255,255,255)">
<div style="margin:0px"><span style="margin:0px; font-size:16px; color:rgb(49,49,49); word-spacing:1px"><font style="font-size:1.125rem"><b>Date:</b> March 2nd, Wednesday</font></span></div>
<div style="margin:0px">
<div style="margin:0px; font-size:16px; color:rgb(49,49,49); word-spacing:1px"><font style="font-size:1.125rem"><b>Time: </b>12:30pm CT</font></div>
<div style="margin:0px; font-size:16px; color:rgb(49,49,49); word-spacing:1px"><font style="font-size:1.125rem"><b>Location: </b>JCL 390</font></div>
<div dir="auto" style="margin:0px; font-size:16px; color:rgb(49,49,49); word-spacing:1px">
<b><font style="font-size:1.125rem"><br>
</font></b></div>
<div dir="auto" style="margin:0px; font-size:16px; color:rgb(49,49,49); word-spacing:1px">
<b><font style="font-size:1.125rem">Speaker: Max Ovsiankin</font></b></div>
<div dir="auto" style="margin:0px; font-size:16px; color:rgb(49,49,49); word-spacing:1px">
<font size="4"><br>
</font></div>
<b style="font-size:16px; word-spacing:1px; color:rgb(49,49,49)"><font style="font-size:1.125rem">Title: </font></b><font size="4">Streaming Algorithms for Ellipsoidal Approximation of Convex Polytopes</font></div>
<div style="margin:0px"><b style="font-size:16px; word-spacing:1px; color:rgb(49,49,49)"><font style="font-size:1.125rem"><br>
</font></b></div>
<div style="margin:0px"><span style="margin:0px; font-size:16px; color:rgb(49,49,49); word-spacing:1px"><font style="font-size:1.125rem"><b>Zoom: </b>[<a href="https://urldefense.com/v3/__https://www.google.com/url?q=https*3A*2F*2Fuchicago.zoom.us*2Fj*2F97375149992*3Fpwd*3DYmNGa1FoaW1WOXVaQ1UxcVBWMjhVdz09&sa=D&ust=1646512430502000&usg=AOvVaw13FTypdW6t1Zcb49FcCVaI__;JSUlJSUlJQ!!BpyFHLRN4TMTrA!olXSZRmsAQcJ9V-Am2ukux9sTIOv2URHyw3af6Qjx16vaA61qQrERZ6jBznjNcU4Zo4$" title="https://www.google.com/url?q=https%3A%2F%2Fuchicago.zoom.us%2Fj%2F97375149992%3Fpwd%3DYmNGa1FoaW1WOXVaQ1UxcVBWMjhVdz09&sa=D&ust=1646512430502000&usg=AOvVaw13FTypdW6t1Zcb49FcCVaI">link</a>]</font></span></div>
<div style="margin:0px"><br>
</div>
<div style="margin:0px">
<div dir="auto" style="margin:0px"><font style="color:rgb(49,49,49); font-size:1.125rem; word-spacing:1px"><b>Abstract: </b>John's theorem is a useful result that says that any symmetric convex body can be well-approximated by some ellipsoid with an approximation
factor that is the square root of the dimension of the body. Ellipsoidal approximations more generally have been applied to approximating the volume of convex bodies and sampling from them using Markov chains, and have been applied in other areas such as online
optimization. We present new streaming algorithms for finding ellipsoidal approximations when these convex bodies are polytopes. These algorithms are well-suited to low-memory or online settings, and their runtime matches that of the best known algorithms
for the offline setting. The approximation factor differs from the offline solution only by a factor sub-logarithmic in the aspect ratio of the polytope. Based on joint work with Naren Manoj and Yury Makarychev.</font></div>
</div>
</div>
<div style="margin:0px; font-size:15px; color:rgb(32,31,30); background-color:rgb(255,255,255)">
<font size="4"><br>
</font></div>
<div style="margin:0px; font-size:15px; color:rgb(32,31,30); background-color:rgb(255,255,255)">
<span style="margin:0px; font-size:large">[<a href="https://urldefense.com/v3/__https://orecchia.net/event/theory-lunch/__;!!BpyFHLRN4TMTrA!olXSZRmsAQcJ9V-Am2ukux9sTIOv2URHyw3af6Qjx16vaA61qQrERZ6jBznjSXXw62M$" target="_blank" rel="noopener noreferrer" title="https://orecchia.net/event/theory-lunch/" style="margin:0px"><span class="x_markyk2ycimeh" style="margin:0px">Theory</span><span> </span><span class="x_mark5lphdspqc" style="margin:0px">Lunch</span><span> </span>Webpage</a>]<br>
[<a href="https://urldefense.com/v3/__https://calendar.google.com/calendar/u/0/embed?src=c_osgf1c1qemdras8mu7l7pdhjrs@group.calendar.google.com&ctz=America*Chicago__;Lw!!BpyFHLRN4TMTrA!olXSZRmsAQcJ9V-Am2ukux9sTIOv2URHyw3af6Qjx16vaA61qQrERZ6jBznjXzVZCW4$" title="https://calendar.google.com/calendar/u/0/embed?src=c_osgf1c1qemdras8mu7l7pdhjrs@group.calendar.google.com&ctz=America/Chicago"><span class="x_markyk2ycimeh" style="margin:0px">Theory</span><span style="margin:0px"> </span><span class="x_mark5lphdspqc" style="margin:0px">Lunch</span><span style="margin:0px"> </span>Calendar</a>]</span></div>
<br>
</div>
</div>
</body>
</html>