# Talks

- “Affine Planes with Polygons” (Georgian Mathematical Union conference, Batumi, September, 2019)
- “Apollonian Proof” (LC 2019, Prague)
- “Ratio Then and Now” (Model Theory and Mathematical Logic: Conference in honor of Chris Laskowski's 60th birthday, June 2019)
- “Conic sections with and without Algebra” (Antalya Algebra Days XXI, May 2019)
- “Euclid Mathematically and Historically” (Bilkent, March 7, 2018)
A Method for Companionability, Applied to Group Actions and Valuations

(11th Panhellenic Logic Symposium, Delphi, July 2017):Thales as originator of the concept of proof

(Thales Kanıt kavramının öncüsü olarak, Thales Buluşması, 24 Eylül 2016)Spaces and Fields

(Istanbul Model Theory Day, April 18, 2016)- “The Compactness Theorem” (a course of three lectures, one hour each, to be given on June 20 and 21, 2015, at the 5th World Congress and School on Universal Logic)
- “The Sense of Proportion in Euclid” (Gebze, May 8, 2015)
- “Matematik Paradoksları” (a talk for students, December 4, 2014)
- “Compactness” (Caucasian Mathematics Conference, Tbilisi, September 5–6, 2014)
- “Geometry as made rigorous by Euclid and Descartes” (Mimar Sinan, October, 2013)
- “Teori zincirleri” (Turkish National Mathematics Symposium, Dicle University, Diyarbakır, September, 2013)
- “Descartes as model-theorist” (Istanbul Model Theory Seminar, May, 2013)
- Sabancı University, March, 2013
- Istanbul Model Theory Seminar, February, 2013
- Mimar Sinan, 2012
- Tabriz, 2012
- Antalya Algebra Days, May, 2010: a poster:
- Çankaya University, 2010 (seminar in the Department of
Mathematics and Computer Science, March 26): “Model theory and
linear algebra”
- Abstract: Like set theory or category theory, model theory
- provides ways of organizing and thinking about (parts of) mathematics, and
- is itself a branch of mathematics like any other, which raises its own questions and (sometimes!) answers them.

- Notes:

- Abstract: Like set theory or category theory, model theory
- Istanbul, 2009 (Conference in Honor of Oleg Belegradek's 60th Birthday, December 5): “Interacting rings” (a revision of the Lyon talk of this year).
- Ankara, 2009 (algebra seminar at METU, November 20): “One
amateur's approach to elliptic curves.”
- Abstract: Every curve has a function field. If two such function fields are isomorphic, then they have the same first-order logical theories. The converse holds as well, unless one of the curves is an elliptic curve with complex multiplication. In this case, the endomorphism ring of the curve turns out to be important. I shall discuss these matters, mainly working over the complex numbers. In particular, I shall use the understanding of an elliptic curve as the complex field modulo a lattice. However, some of the results can be proved over arbitrary fields of arbitrary characteristic.
- Notes:

- Lyon, 2009 (the Logicum Urbanae Lugduni):
- Bern, 2008:
- Antalya, 2006 (MODNET Midterm Meeting):
- Nijmegen, 2006:
- Athens, 2005:
- Istanbul, 2005 (Istanbul Bilgi University mathematics department)
- Ankara, 2003: METU philosophy department:
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