Hi, my name is İrem Portakal*.

''İ'' is the uppercase of "i" in Turkish. It is pronanciated for example as the german letter "i".

About Me

I am a postdoc in Nonlinear Algebra Research Group of Prof. Bernd Sturmfels at the Max Planck Institute Leipzig. Before that I was a postdoc researcher in the Discrete, Convex and Toric Geometry research group of Benjamin Nill at Otto-von-Guericke-Universität Magdeburg. I defended my thesis in April 2018 at Freie Universität Berlin. I was a PHD Student in Berlin Mathematical School and in the Algebraic Geometry Group of Klaus Altmann. Before, I was a master student at École Normale Supérieure in Lyon and an undergraduate student at Galatasaray University in Istanbul, Turkey.

Some key words for my research: Deformation, rigidity, toric, T-varieties, edge cones, edge polytopes, lattice polytopes, rational maximum likelihood estimators, rational linear precision, Horn matrix, matrix Schubert varieties, Kazhdan-Lusztig varieties.

I was the speaker of the special lecture "Visualizing Hyperbolic Geometry" in celebration of Women in Mathematics Day in 2021 at KWIM (Konstanz Women in Mathematics). No preknowledge on (hyperbolic) geometry is required. You can watch it here .



Ongoing projects

  • Complexity of the usual torus action on Kazhdan-Lusztig varieties, with Maria Donten-Bury and Laura Escobar-Vega
    • We investigate the class of Kazhdan-Lusztig varieties, and its subclass of matrix Schubert varieties, endowed with a naturally defined torus action. We give a combinatorial description of the weight cone of a Kazhdan-Lusztig variety. We also construct and investigate examples of Kazhdan-Lusztig varieties where the considered action has small complexity. Finally, we introduce a recipe for constructing families of complexity-d T-varieties of same dimension.


Otto-von-Guericke-Universität Magdeburg

WiSe 20/21

SoSe 20

WiSe 19/20

SoSe 19

WiSe 18/19

SoSe 18

Freie Universität Berlin

WiSe 17/18


Galatasaray University


  • Analyse à une variable I-II, Introduction à la géométrie torique.
  • Abstract Algebra Exercise Session.


E-mail: mail [at] domain

where domain = irem-portakal.de