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<div align="center"><big><b><big>Welcome to the 2022 Fall talks
of ODTU-Bilkent Algebraic Geometry Seminars</big></b></big><b><br>
</b></div>
<div align="center"><i>since 2000</i><br>
</div>
<div align="center"><b><b>=================================================================</b></b><br>
<br>
This week the <a
href="http://www.bilkent.edu.tr/~sertoz/agseminar.htm"
target="_blank" moz-do-not-send="true">ODTU-Bilkent
Algebraic Geometry Seminar</a> is <b>online</b><br>
<br>
<i><font color="#ff00ff">This talk will begin at <u><b>15:40</b></u><u> (GMT+3)</u></font></i><br>
<a
href="https://www.timeanddate.com/worldclock/fixedtime.html?msg=ODT%C3%9C-Bilkent+Algebraic+Geometry+Seminar&iso=20221125T1540&p1=19"
target="_blank" moz-do-not-send="true">Please check your
time difference between Ankara and your city here</a><br>
<b>=================================================================</b></div>
<div align="center"><br>
<img src="cid:part1.hv2FeWZO.4H43CI7d@bilkent.edu.tr" alt="">
<div align="center"><b> </b></div>
<font size="2"><i>Erin Hanson</i></font><br>
<div align="left"><b><b><font color="#ff0000">Speaker:<font
color="#000000"> Davide Cesare Veniani<br>
</font></font></b></b><b><b><font color="#ff0000">Affiliation:
<font color="#000000"><i>Stuttgart</i></font></font></b></b><b><b><font
color="#ff0000"><br>
Title:<font color="#000000"> Non-degeneracy of
Enriques surfaces<br>
</font><br>
</font></b></b></div>
</div>
<div align="left"><b><b><font color="#ff0000">Abstract:</font></b></b><font
color="#ff0000"><font color="#000000"> Enriques' original
construction of Enriques surfaces involves a
10-dimensional family of sextic surfaces in the projective
space which are non-normal along the edges of a
tetrahedron. The question whether all Enriques surfaces
arise through Enriques' construction has remained open for
more than a century.<br>
<br>
In two joint works with G. Martin (Bonn) and G. Mezzedimi
(Hannover), we have now settled this question in all
characteristics by studying particular configurations of
genus one fibrations, and two invariants called maximal
and minimal non-degeneracy. The proof involves so-called
`triangle graphs' and the distinction between special and
non-special 3-sequences of half-fibers.<br>
<br>
In this talk, I will present the problem and explain its
solution, illustrating further possible developments and
applications.</font></font></div>
<div align="left"><font color="#ff0000"><font color="#000000">
<br>
</font></font></div>
<div align="left"><font color="#ff0000"><font color="#000000"><b><font
color="#ff0000">Date:<font color="#000000"> 25
November 2022</font></font></b>, <b>Friday</b></font></font><br>
</div>
<div align="left"><font color="#ff0000"><font color="#000000"><b><font
color="#ff0000">Time: </font>15:40 <i>(GMT+3)</i></b><br>
<b><font color="#ff0000">Place: </font></b><font
color="#ff0000"><font color="#000000"><b>Zoom</b></font></font></font></font></div>
<blockquote>
<p><font color="#ff0000"><font color="#000000"><font
color="#ff0000"><font color="#000000"><b><b
style="color:rgb(51,51,51);font-family:arial,verdana,sans-serif;font-size:14px">One
day before the seminar, an announcement with the
Zoom meeting link will be sent to those who
registered with Sertöz.<br>
</b></b></font></font></font></font></p>
<p><font color="#ff0000"><font color="#000000"><font
color="#ff0000"><font color="#000000"><b><b
style="color:rgb(51,51,51);font-family:arial,verdana,sans-serif;font-size:14px">If
you have registered before for one of the
previous talks, there is no need to register
again; you will automatically receive a link for
this talk too.<br>
</b></b></font></font></font></font></p>
<p><font color="#ff0000"><font color="#000000"><font
color="#ff0000"><font color="#000000"><b><b
style="color:rgb(51,51,51);font-family:arial,verdana,sans-serif;font-size:14px">If
you have not registered before, please contact
him at <a
href="mailto:sertoz@bilkent.edu.tr?subject=Zoom%20Seminar%20Address%20Request"
target="_blank" moz-do-not-send="true">sertoz@bilkent.edu.tr</a>.</b></b></font></font></font></font></p>
</blockquote>
<div align="left"><br>
</div>
<div align="left">You are most cordially invited to attend.</div>
<div align="left"><br>
</div>
<div align="left">Ali Sinan Sertöz</div>
<div align="left"><br>
</div>
<hr>
<pre cols="72">----------------------------------------------------------------------------
Ali Sinan Sertöz
Bilkent University, Department of Mathematics, 06800 Ankara, Türkiye
Office: (90)-(312) - 290 1490
Department: (90)-(312) - 266 4377
Fax: (90)-(312) - 290 1797
e-mail: <a href="mailto:sertoz@bilkent.edu.tr" target="_blank" moz-do-not-send="true" class="moz-txt-link-freetext">sertoz@bilkent.edu.tr</a>
Web: <a href="http://sertoz.bilkent.edu.tr" target="_blank" moz-do-not-send="true">sertoz.bilkent.edu.tr</a>
----------------------------------------------------------------------------</pre>
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