ALCYON lab

ALgorithms for
Combinatorics,
geometrY,
Optimization and
Number theory
Home Members Projects Publications SCIM Theses topics Alumni

In ALCYON (Algorithms for Combinatorics, Geometry, Optimization and Number Theory) we work on Symbolic Computation. Both on the mathematics to improve algorithms and on the efficient (high performance) implementations of algorithms in order to push mathematics further. Symbolic Computation lies in the intersection of mathematics and computer science. This means that it is both 100% mathematics and 100% computer science.
If you want to join us, fill in this form.
ALCYON participates in the Symbolic Computation Istanbul Meetings
If you are interested to work on a project (graduation project, master thesis, PhD, research project), you can check possible thesis topics.

News

01 July 2025

ACA 2025 - Applications of Computer Algebra
In July 2025 we organize ACA in Heraklion (Greece).

Events

Applications of Computer Algebra 2025 01 July 2025 Greece
Symbolic Computation: Algorithms, Learning and Engineering 2022 08 August 2022 Turkey
Computer Algebra in Scientific Computing 2022 26 August 2022 Turkey
Applications of Computer Algebra 2022 15 August 2022 Turkey

Members

Fatma Karaoğlu Faculty Gebze TU
Tulay Ayyildiz Faculty Gebze TU
Elias Tsigaridas Associate Faculty Inria/IMJ-PRG
Mohan Ravichandran Associate Faculty
Zafeirakis Zafeirakopoulos Researcher University of Geneva
Deniz Naz Demirel MSc Student Middle East Technical University
Baran Solmaz MSc Student Gebze TU
Başak Karakaş MSc Student Gebze TU
Ismail Tapan Undergraduate Student Gebze TU

Projects

Ongoing
2022 Oct-
2025 Oct
Polyhedral Omega: Generalizations and Applications - POGA TUBITAK 1001 ~50k euro
Concluded
2019 Jun-
2022 Jun
Gröbner Bases, Resultants and Polyhedral Geometry - GRAPE Bilateral Project with France - TUBITAK 2509 ~50k euro
2017 Mar-
2019 Jul
A system for efficient representation of mathematical data and benchmarking of mathematical software and algorithms TUBITAK 3001 ~17k euro
2017 Oct-
2020 Oct
Heterogeneous Algorithms for Combinatorics, Geometry, Optimization and Number Theory - HALCYON TUBITAK 3501 ~80k euro
2019 Nov-
2021 Nov
Zero dimensional Hermite method TUBITAK 3501 ~25k euro
2018 Oct-
2020 Feb
Algebraic Motion Planning Reasearch Council of Gebze Technical University ~3k euro
2016 Aug-
2017 Feb
Parallel Computation of Discrete and Continuous Volume Reasearch Council of Gebze Technical University ~3k euro

Publications

Books
2020 Daniel Slamanig, Elias P. Tsigaridas, Zafeirakis Zafeirakopoulos - "Mathematical Aspects of Computer and Information Sciences - 8th International Conference, MACIS 2019" - Springer LNCS.
Conference Papers
2024 Tulay Ayyildiz, Deniz Naz Demirel, Ismail Tapan, Zafeirakis Zafeirakopoulos - "A Julia package for Polyhedral Omega and applications" - ISSAC 2024.
2020 Christina Katsamaki, Fabrice Rouillier, Elias P. Tsigaridas, Zafeirakis Zafeirakopoulos - "On the geometry and the topology of parametric curves" - ISSAC 2020.
2020 Christina Katsamaki, Fabrice Rouillier, Elias P. Tsigaridas, Zafeirakis Zafeirakopoulos - "PTOPO - a maple package for the topology of parametric curves." - ISSAC 2020.
2019 Umutcan Önal and Zafeirakis Zafeirakopoulos - "A Machine Learning Framework for Volume Prediction" - Analysis of Experimental Algorithms - SEA 2019.
2017 Vissarion Fisikopoulos, Zafeirakis Zafeirakopoulos - "Experimental Study of the Ehrhart Interpolation Polytope" - Mathematical Aspects of Computer and Information Sciences - MACIS 2017.
2017 Ioannis Z. Emiris, Anna Karasoulou, Eleni Tzanaki, Zafeirakis Zafeirakopoulos - "On the space of Minkowski summands of a convex polytope" - EuroCG '16.
2015 Ioannis Z. Emiris, Christos Konaxis, Zafeirakis Zafeirakopoulos - "Minkowski Decomposition and Geometric Predicates in Sparse Implicitization" - 40th International Symposium on Symbolic and Algebraic Computation - ISSAC.
2013 Christos Koukouvinos, Dimitris E. Simos, Zafeirakis Zafeirakopoulos - "A Gröbner Bases Method for Complementary Sequences" - Proceedings of Applications of Computer Algebra ACA 2013.
2009 Michael Hemmer, Elias P. Tsigaridas, Zafeirakis Zafeirakopoulos, Ioannis Z. Emiris, Menelaos I. Karavelas, Bernard Mourrain - "Experimental evaluation and cross-benchmarking of univariate real solvers" - Symbolic Numeric Computation - SNC 2009.
Journal Papers
2023 Christina Katsamaki, Fabrice Rouillier, Elias P. Tsigaridas, Zafeirakis Zafeirakopoulos - "PTOPO: Computing the geometry and the topology of parametric curves" - Journal of Symbolic Computation.
2017 Felix Breuer, Zafeirakis Zafeirakopoulos - "Polyhedral Omega: a New Algorithm for Solving Linear Diophantine Systems" - Annals of Combinatorics.
2016 Matthias Beck, Benjamin Braun, Matthias Köppe, Carla D. Savage, Zafeirakis Zafeirakopoulos - "Generating Functions and Triangulations for Lecture Hall Cones" - SIAM Journal on Discrete Mathematics.
2014 Matthias Beck, Benjamin Braun, Matthias Köppe, Carla D. Savage, Zafeirakis Zafeirakopoulos - "s-Lecture hall partitions, self-reciprocal polynomials, and Gorenstein cones" - The Ramanujan Journal.
2014 Angelos Mantzaflaris, Hamid Rahkooy, Zafeirakis Zafeirakopoulos - "Efficient computation of dual space and directional multiplicity of an isolated point" - Computer Aided Geometric Design.
2011 Christos Koukouvinos, Veronika Pillwein, Dimitris E. Simos, Zafeirakis Zafeirakopoulos - "On the average complexity for the verification of compatible sequences" - Information Processing Letters.
Talks (Invited & Symposia w/o Proceedings)
Theses
2019 Nurdan Ünlü - "Toric h-numbers of dual hypersimplices and Chow-Betti numbers abd Ehrhart polynomials of Minkowski sums with segments" - MSGSU.
2019 Büşra Sert - "A Study on the Chamber Complex" - MSGSU.
2012 Zafeirakis Zafeirakopoulos - "Linear Diophantine Systems: Partition Analysis and Polyhedral Geometry" - Research Institute for Symbolic Computation / DK-compmath.
2008 Zafeirakis Zafeirakopoulos - "Study and Benchmarks for Real Root Isolation methods" - Departments of Informatics and Telecommunication.