3 citations · 5 across the 13 of their papers we have counts for
15 papers
Stable Coexistence in Ecologies and Games
Türkü Özlüm Çelik, Vincenzo Antonio Isoldi, Irem Portakal +1
We study feasible stable equilibria of Lotka-Volterra systems and their higher-order extensions. We complete the classification of impossible ecological interaction networks with a…
On the dimensions of correlated equilibrium polytopes of generic games
Jan Draisma, Linda Hoyer, Irem Portakal
In this paper, we study the dimension of the correlated equilibrium polytope of finite games. Under the oriented-matroid notion of genericity, we prove that if a generic game is no…
Totally mixed conditional independence equilibria of generic games
Matthieu Bouyer, Irem Portakal, Javier Sendra-Arranz
This paper further develops the algebraic--geometric foundations of conditional independence (CI) equilibria, a refinement of dependency equilibria that integrates conditional inde…
A vector bundle approach to Nash equilibria
Hirotachi Abo, Irem Portakal, Luca Sodomaco
We use vector bundles to study the locus of totally mixed Nash equilibria of an -player game in normal form, which we call the Nash equilibrium scheme. When the payoff tensor fo…
Dependency equilibria: Boundary cases and their real algebraic geometry
Irem Portakal, Daniel Windisch
This paper is a significant step forward in understanding dependency equilibria within the framework of real algebraic geometry encompassing both pure and mixed equilibria. In alig…
Game theory of undirected graphical models
Irem Portakal, Javier Sendra-Arranz
An -player game in normal form can be modeled via undirected discrete graphical models where the discrete random variables represent the players and their state spaces are t…
Toric Ideals of Characteristic Imsets via Quasi-Independence Gluing
Benjamin Hollering, Joseph Johnson, Irem Portakal +1
Characteristic imsets are 0-1 vectors which correspond to Markov equivalence classes of directed acyclic graphs. The study of their convex hull, named the characteristic imset poly…
Combinatorics of Correlated Equilibria
Marie-Charlotte Brandenburg, Benjamin Hollering, Irem Portakal
We study the correlated equilibrium polytope of a game from a combinatorial point of view. We introduce the region of full-dimensionality for this class of polytopes and…
Nash conditional independence curve
Irem Portakal, Javier Sendra-Arranz
We study the Spohn conditional independence (CI) variety of an -player game for undirected graphical models on binary random variables consisting of one edge. For…
Geometry of Dependency Equilibria
Irem Portakal, Bernd Sturmfels
An -person game is specified by tensors of the same format. We view its equilibria as points in that tensor space. Dependency equilibria are defined by linear constraints on…
Complexity of the usual torus action on Kazhdan-Lusztig varieties
Maria Donten-Bury, Laura Escobar, Irem Portakal
We investigate the class of Kazhdan-Lusztig varieties, and its subclass of matrix Schubert varieties, endowed with a naturally defined torus action. Writing a matrix Schubert varie…
Rigid Gorenstein toric Fano varieties arising from directed graphs
Selvi Kara, Irem Portakal, Akiyoshi Tsuchiya
A directed edge polytope is a lattice polytope arising from root system and a finite directed graph . If every directed edge of belongs to a directed c…
Rigid toric matrix Schubert varieties
Irem Portakal
For a given permutation , Fulton proves that the matrix Schubert variety can be defined via certain rank conditions encoded…
On rigidity of toric varieties arising from bipartite graphs
Irem Portakal
One can associate to a bipartite graph a so-called edge ring whose spectrum is an affine normal toric variety. We characterize the faces of the (edge) cone associated to this toric…
A note on deformations and mutations of fake weighted projective planes
Irem Portakal
It has been shown by Hacking and Prokhorov that if the projective surface X with quotient singularities and self-intersection number 9 has a smoothing to the projective plane, then…