Welcome to the 2026
Spring talks of ODTÜ-Bilkent Algebraic Geometry
Seminars
since 2000
Ben Viegers (1886-1947)
Affiliation: Galatasaray
& Polish Academy
Title: Newton-nondegenerate
line singularities, Lê numbers and Bekka
(c)-regularity
Abstract:
Consider an analytic function f(t,z) defined in a
neighbourhood of the origin of C x Cn such that for
all t, the function ft(z):=f(t,z) defines a
hypersurface of Cn with a line singularity at 0∈Cn .
Denote by V(f) the hypersurface of C x Cn defined by
f(t,z) and write Σf for its singular locus. We assume
that ft is ''quasi-convenient'' and Newton
nondegenerate. Within this framework, we show that if
the Lê numbers of ft are independent of t for all
small t, then Σf is smooth and V(f)\Σf is Bekka
(c)-regular over Σf. This is a version for line
singularities of a result of Abderrahmane concerning
isolated singularities.
As a corollary, we obtain that any family of
quasi-convenient, Newton non-degenerate, line
singularities with constant Lê numbers as above is
topologically equisingular. In particular, this
applies to families with non-constant Newton diagrams,
and therefore extends, in some direction, a result
previously observed by Damon.
This is a joint work with Christophe Eyral.
Date: 20 February 2026,
Friday
Time: 15:40 (GMT+3)
Place: Zoom
Participants who have registered will receive
the Zoom link via email one day before the
seminar.
If you registered for a previous talk in this
series, there's no need to register again—you'll
automatically receive the link for this session.
If you
haven't registered yet, please contact sertoz@bilkent.edu.tr
to be added to the mailing list.
You are most cordially invited to
attend.
Ali Sinan Sertöz
This seminar series is
organized by a joint team from ODTÜ and
Bilkent
Alexander Degtyarev (Bilkent)
Ali Sinan Sertöz (Bilkent) contact
person
Ali Ulaş Özgür Kişisel (ODTÜ)
Yıldıray Ozan (ODTÜ)
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Ali Sinan Sertöz
Bilkent University, Department of Mathematics, 06800 Ankara, Türkiye
Office: (90)-(312) - 290 1490
Department: (90)-(312) - 266 4377
e-mail: sertoz@bilkent.edu.tr
Web: sertoz.bilkent.edu.tr
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