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<div align="center"><big><b><big>Welcome to the 2023
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">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=20231103T1540&p1=19&ah=1"
target="_blank">Please check your time difference
between Ankara and your city here</a><br>
<b>=================================================================</b></div>
<div align="center">
<div align="center"><img
src="cid:part1.q7kkwy5F.z4tstW4v@bilkent.edu.tr"
alt="" class="" width="510" height="472"></div>
<div align="center"><b><br>
</b><i>Johannes Vermeer (1632-1675)<br>
Diana and her companions (1653)</i><br>
</div>
<div align="left"><b><b><font color="#ff0000">Speaker:
</font><a
href="https://avesis.agu.edu.tr/cisem.aktasgunes">Çisem Güneş Aktaş</a><font
color="#ff0000"><font color="#000000"> <br>
</font></font></b></b><b><b><font
color="#ff0000">Affiliation: </font><i>Abdullah
Gül</i></b></b><b><b><font color="#ff0000"><br>
Title:<font color="#000000"> Geometry of
equisingular strata of quartic surfaces with
simple singularities</font></font></b></b><br>
<b><b><font color="#ff0000"><font color="#000000"> </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"> </font></font><br>
<div align="justify"><font color="#ff0000"><font
color="#000000">The geometry of the equisingular
strata of curves, surfaces, etc. is one of the
central problems of K3-surfaces. Thanks to the
global Torelli theorem and surjectivity of the
period map, the equisingular deformation
classification of singular projective models of
K3-surfaces with any given polarization becomes
a mere computation. The most popular models
studied intensively in the literature are plane
sextic curves and spatial quartic surfaces.
Using the arithmetical reduction, Akyol and
Degtyarev [1] completed the problem of
equisingular deformation classification of
simple plane sextics. Simple quartic surfaces
which play the same role in the realm of spatial
surfaces as sextics do for curves, are a
relatively new subject, promising interesting
discoveries.<br>
<br>
In this talk, we discuss the problem of
classifying quartic surfaces with simple
singularities up to equisingular deformations by
reducing the problem to an arithmetical problem
about lattices. This research [3] originates
from our previous study [2] where the
classification was given only for nonspecial
quartics, in the spirit of Akyol ve Degtyarev
[1]. Our principal result is extending the
classification to the whole space of simple
quartics and, thus, completing the equisingular
deformation classification of simple quartic
surfaces.<br>
<br>
[1] Akyol, A. ve Degtyarev, A.,
2015. Geography of irreducible plane sex- tics.
Proc. Lond. Math. Soc. (3), 111(6), 13071337.
ISSN 0024-6115. doi:10.1112/plms/pdv053.<br>
[2] Güneş Aktaş, Ç, 2017.
Classification of simple quartics up to equisin-
gular deformation. Hiroshima Math. J., 47(1),
87112. ISSN 0018-2079.
doi:10.32917/hmj/1492048849.<br>
<br>
[3] Güneş Aktaş, Ç, to appear in
Deformation classification of quartic surfaces
with simple singularities. Rev. Mat. Iberoam.
doi:10.4171/RMI/1431</font></font><font
color="#ff0000"><font color="#000000"><br>
</font></font></div>
</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"> 3 November 2023</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">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"><font size="1"><i>(PS: To unsubscribe
from this list please send me a note.)</i></font>
</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"
class="gmail-moz-txt-link-freetext moz-txt-link-freetext">sertoz@bilkent.edu.tr</a>
Web: <a href="http://sertoz.bilkent.edu.tr" target="_blank">sertoz.bilkent.edu.tr</a>
----------------------------------------------------------------------------</pre>
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