Genelleştirilmiş Hipergeometrik Fonksiyonlar Cinsinden Cebirsel Fonksiyonlar

Mutlu Koçar, Galatasaray Üniversitesi

24/05/2019, Saat: 10:30

Yer: B256

Özet: Bu konuşmanın ilk kısmında, verilen bir cebirsel denklemin orijin civarındaki kesirli kuvvet serisini bulmak için kullanılan Newton-Puiseux algoritmasını anlamaya çalışacağız. İkinci kısımda, genel üç terimli bir cebirsel denklemin çözümlerinin Mellin dönüşümünü tasvir edeceğiz.  Son kısımda, verilen genel üç terimli özel koşulları sağlayan cebirsel denklemin çözümlerini Mellin dönüşümü ve Newton-Puiseux algoritması kullanarak elde edeceğiz. Buna ek olarak, son kısımda bahsi geçen cebirsel denklemin çözümleri tarafından sağlanan hipergeometrik tip diferansiyel denklemi elde edeceğiz.

Riemann Zeta fonksiyonunun analitik devamlılığı

Sedef Taşkın (DEU)

03/05/2019, Saat: 10:00

Yer: B256

1860′ ta çığır açan raporunda Riemann, zeta fonksiyonunun asalların dağılımını anlamadaki rolünün çok önemli olduğunu gösterdi. Riemann, zeta fonksiyonunun analitik genişlemesini, sadece s=1′ de basit tekilliğiyle beraber, ispatladı. Bu konuşmada öncelikle gamma fonksiyonunu tanıtacağız. Daha sonra zeta fonksiyonunun analitik genişlemesinden bahsedeceğiz. Son olarak zeta fonksiyonunun fonksiyonel denklemini elde edeceğiz.

Arithmetica İzmir 2

10 Mayıs 2019 Cuma düzenlenecek olan Arithmetica İzmir 2 Çalıştayı için son başvuru tarihi 2 Mayıs 2019’dur. Çalıştayımız MAD projesi kapsamında Türk Matematik Derneği tarafından desteklenmektedir. Türk Matematik Derneği’ne (TMD) ve MAD projesine destekleri için çok teşekkür ediyoruz.

Yer: Dokuz Eylül Üniversitesi, Matematik Bölümü, B256

Tarih: 10 Mayıs 2019

Başvuru formu için tıklayınız

Davetli Konuşmacılar

Ali Ulaş Özgür Kişisel, Orta Doğu Teknik Üniversitesi

Ayberk Zeytin, Galatasaray Üniversitesi

Ekin Özman, Boğaziçi Üniversitesi

Yıldırım Akbal, Atılım Üniversitesi

Program ve Özetler

9:15—9:30: Açılış

9:30—10:45: Ali Ulaş Özgür Kişisel

10:45—11:15: Çay-Kahve molası

11:15—12:30: Ekin Özman

12:30—14:30: Öğle arası

14:30—15:45: Yıldırım Akbal

15:45—16:15: Çay-Kahve molası

16:15—17:30: Ayberk Zeytin

Ali Ulaş Özgür Kişisel, Orta Doğu Teknik Üniversitesi

Title: Line Arrangements Over Different Base Fields 

Abstract: There are various obstructions regarding the existence of line arrangements in the projective plane over a given base field. In this talk, some of these obstructions and how they depend on the chosen base field will be explained. 

Ekin Özman, Boğaziçi Üniversitesi

Title: Modularity, rational points and Diophantine Equations

Abstract: Understanding solutions of Diophantine equations over rationals or more generally over any number field is one of the main problems of number theory. One of the most spectacular recent achievement in this area is the proof of Fermat’s last theorem by Wiles. By the help of the modular techniques used in this proof and its generalizations it is possible to solve other Diophantine equations too.  Understanding quadratic points on the classical modular curve or rational points on its twists play a central role in this approach. In this talk, I will summarize the modular method and mention some recent results about points on modular curves. This is joint work with Samir Siksek.

Yıldırım Akbal, Atılım Üniversitesi

Title: Waring’s Problem, Exponential Sums and Vinogradov’s Mean Value Theorem    

Abstract: Having introduced Hardy&Littlewood Circle method, we will jump to Waring’s Problem: representability of a large integer as the sum of s kth powers of positive integers,  which was the main motivation of Vinogradov to study a system equations (called Vinogradov’s system). Next we move on Vinogradov’s mean value theorem: a non-trivial upper-bound on the number of solutions to Vinogradov’s system, and then mention the milestone contributions of Vinogradov, Wooley and Bourgain (rip) et al.  
Last but not least, some applications of Vinogradov’s mean value theorem on exponential sums will be given. 

Ayberk Zeytin, Galatasaray Üniversitesi

Title: Arithmetic of Subgroups of PSL2(Z)

Abstract: The purpose of the talk is to introduce certain arithmetic questions from a combinatorial viewpoint. The fundamental object is the category of subgroups of the modular group and its generalizations. I will try to present the different nature of arithmetic of subgroups of finite and infinite index  and their relationship to classical problems. I plan to  formulate specific questions at the very end of the presentation and, if time permits, our contribution to both worlds. 
This is partly joint with M. Uludag

Cebirsel ve Uygulamalı Topoloji Çalıştayı

Cebirsel ve Uygulamalı Topoloji Çalıştayı
Dokuz Eylül Üniversitesi, İzmir
19 Nisan, 2019


Bu çalıştayın amacı, ülkemizde Cebirsel Topoloji ve Uygulamalı Topoloji alanlarında çalışan araştırmacıları bir araya getirerek, kendi alanlarındaki bilgi birikimlerini diğer araştırmacılarla paylaşmalarını ve  ortak proje fikirlerini paylaşarak yeni işbirlikleri başlatmalarını sağlamaktır.

Öğleden önceki konuşmalar, Matematik Bölümü, B256 numaralı sınıfta; öğleden sonraki konuşmalar ise Matematik Bölümü B258 numaralı sınıfta yapılacaktır. Daha fazla bilgi için, asli.ilhan at .deu.edu.tr adresine e-mail atabilirsiniz.

Program

10:00-11:00 Ayşe Borat
11:00-11:20 Ara
11:20-12:10 Matthew Gelvin
12:10-14:00 Öğle Arası
14:00-14:50 Mehmet Akif Erdal
14:50-15:00 Ara
15:00-15:50 Hanife Varlı
15:50-16:00 Ara
16:00-16:30 Sabri Kaan Gürbüzer
16:30-16:40 Ara
16:40-17:10 Derya Bayrıl Aykut

A Survey on Topological Robotics
Ayşe Borat

Topological robotics is a field initiated by Michael Farber in 2003. This new field tries to answer topological questions which are inspired by robotics and engineering. In this talk, we will give a brief survey in topological robotics mainly focusing on an important homotopy invariant called Topological Complexity which measures how far a space away from admitting a motion planning algorithm.

Euler Characteristics of Categories and Control of Homotopy Type
Matthew Gelvin

The Euler characteristic of a simplicial complex is a well-known and important combinatorial invariant. When considering small categories and their geometric realizations, one might hope that there is a similar invariant, ideally one that generalizes the classical Euler characteristic in the case of posets. Leinster defined such an object and proved some of its basic properties.

In this talk, I will outline Leinster’s notion of the Euler characteristic of a category and describe how it was used in joint work with Jesper Møller to guide our search for objects that control the homotopy type of certain categories that arise in the study of p-local finite groups.

Fibration Categories from Enrichments
Mehmet Akif Erdal

Fibration categories, as introduced by Brown [1], provide convenient models for homotopy theories as weaker alternatives to model categories. In this talk we will discuss fibration category structures that are induced by enrichments in symmetric monoidal model categories. We will also show that various categories of operator algebras, including Schocket and Uuye’s homotopy theory for $C^*$-algebras [4,5], and their equivariant versions are examples of fibration categories induced by enrichments. By using this, we recover known results that equivariant $KK$-theories and $E$-theories are triangulated categories (see [2,3]).

References
  1. Kenneth S. Brown. Abstract homotopy theory and generalized sheaf cohomology. Trans. Amer. Math. Soc., 186:419–458, 1973.
  2. Ralf Meyer and Ryszard Nest. The baum–connes conjecture via localisation of categories. Topology, 45(2):209–259, 2006.
  3. Ryszard Nest and Christian Voigt. Equivariant Poincar ́e duality for quantum group actions. Journal of Functional Analysis, 258(5):1466–1503, 2010.
  4. Claude Schochet. Topological methods for c-algebras. i. spectral sequences. Pacific Journal of Mathematics, 96(1):193–211, 1981.
  5. Otgonbayar Uuye. Homotopical algebra for $C^*$-algebras. Journal of Non- commutative Geometry, 7(4):981–1006, 2013.

Discrete (and Smooth) Morse Theory
Hanife Varlı

The primary concern of Morse theory is the relation between spaces and functions. The center of interest lies in how the critical points of a function defined on a space affect the topological shape of the space and conversely. Discrete Morse theory, developed by Robin Forman, is a discrete version of Morse theory that turned out to be also an efficient method to study of the topology of the discrete objects such as simplicial and cellular complexes.

In this talk, we will briefly mention smooth Morse theory, then talk about discrete Morse theory. In particular, we will talk about perfect discrete Morse functions, and the problem of composing and decomposing perfect discrete Morse functions on the connected sum of triangulated manifolds.

On a Decomposition of the Bicomplex of Planar Binary Trees
Sabri Kaan Gürbüzer

In this talk, we will introduce some simplicial properties of the set of planar binary trees and a decomposition of the bicomplex into vertical towers given Frabetti [1].

References
  1. Frabetti, A., Simplicial properties of the set of planar binary trees. Journal of Algebraic Combinatorics, 32, 41-65,(2001).

On the Lie Algebra of Spatial Kinematics
Derya Bayrıl Aykut

A spatial displacement is a composition of a spatial rotation followed by a spatial translation. There is an invariant line of these transformations, called screw axis. In this talk we will mention about velocity analaysis of a general spatial motion.

References
  1. TSAI, Lung-Wen (1999). Robot Analysis: The Mechanics of Serial and Parallel Ma- nipulators . A Wiley-Interscience Publication
  2. Selig, J. M. (2005). Geometric Fundamentals of Robotics. Springer(USA).

Eğriler Üzerindeki Rasyonel Noktalar

Hikmet Burak Özcan (DEU)

Tarih ve Zaman: 29/03/2019, Saat:10:00

Yer: B256

Bu konuşmada, ilk olarak bir eğri üzerindeki rasyonel nokta tanımını vererek başlayacağız. Ardından eğriler üzerindeki rasyonel noktaları bulma problemini ele alacağız. Bilinen bir rasyonel noktadan nasıl yeni bir rasyonel nokta bulabileceğimizin tarifini vereceğiz. Daha sonra eliptik eğrilere kısa bir başlangıç yapacağız ve eliptik eğriler üzerindeki rasyonel noktalara değineceğiz. Son olarak da önemli sonuçlardan olan Mordell ve Siegel Teoremlerini konuşacağız. 

Probabilistic Methods in Number Theory

Doga Can Sertbaş, Cumhuriyet University

Tarih ve Saat: 22/03/2019, Saat: 10:00

Yer: B256, DEU Matematik Bölümü

In 1947, Erdos gave a lower bound for the diagonal Ramsey numbers R(k,k). His proof contains purely probabilistic arguments where the original problem is not related to the probability theory. This pioneering work of Erdos gave rise to a new proof technique which is so called the probabilistic method. According to this method, one just obtains the existence of a particular mathematical object in a non-constructive way. In this talk, we first introduce the Ramsey numbers and then explain the basics of the probability theory. After mentioning the fundamentals of the probabilistic method, we give several examples from the number theory. In particular using probabilistic inequalities, we show how one can prove some number theoretic results which seem completely unrelated to the probability theory.

Knotted Strings in the plane


Neslihan Güğümcü
, Atina Teknik Üniversitesi

Tarih: 15/03/2019, Saat:10:00

Yer: B256, DEU Matematik Bölümü

Özet: Planar curves have been studied since the time of Gauss. Gauss was one of the first to notice that they can be handled combinatorially by codes (named as Guass codes) that are strings of labels encoding self-intersections. Whitney classified all immersed curves up to a topological relation called regular homotopy by using the winding number of immersion maps. In the first half of the 20th century Reidemeister showed that classical knot theory is equivalent to the study of immersed curves in the plane, whose self-intersections are endowed with a combinatorial structure, with an under/over-data. With this extra structure, regular homotopy needs to transforms into a richer equivalence relation generated by Reidemeister moves. Since then knot theory is a classical subject of topology, bringing us many interesting questions relating to combinatorial topology.

In this talk, we will talk about knotoids (introduced by Turaev) that provide us a new diagrammatic theory that is an extension of classical knot theory. Problem of classifying knotoids lies at the center of the theory of knotoids. We will construct a Laurent polynomial with integer coefficients for knotoids called the affine index polynomial and we will show how it contributes to the classification problem.