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Related papers: Nash Equilibrium Existence without Convexity

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This work proposes a novel distributed approach for computing a Nash equilibrium in convex games with merely monotone and restricted strongly monotone pseudo-gradients. By leveraging the idea of the centralized operator extrapolation method…

Optimization and Control · Mathematics 2025-07-18 Tatiana Tatarenko , Angelia Nedich

An axiomatic characterization of Nash equilibrium is provided for games in normal form. The Nash equilibrium correspondence is shown to be fully characterized by four simple and intuitive axioms, two of which are inspired by contraction and…

Theoretical Economics · Economics 2025-12-04 Michele Crescenzi

The notion of fault tolerant Nash equilibria has been introduced as a way of studying the robustness of Nash equilibria. Under this notion, a fixed number of players are allowed to exhibit faulty behavior in which they may deviate…

Theoretical Economics · Economics 2022-05-13 Deepanshu Vasal , Randall Berry

Every real algebraic variety is isomorphic to the set of totally mixed Nash equilibria of some three-person game, and also to the set of totally mixed Nash equilibria of an $N$-person game in which each player has two pure strategies. From…

Algebraic Geometry · Mathematics 2007-05-23 Ruchira S. Datta

We show that the problem of finding an {\epsilon}-approximate Nash equilibrium in an anonymous game with seven pure strategies is complete in PPAD, when the approximation parameter {\epsilon} is exponentially small in the number of players.

Computer Science and Game Theory · Computer Science 2014-12-19 Xi Chen , David Durfee , Anthi Orfanou

It is known that the set of all correlated equilibria of an n-player non-cooperative game is a convex polytope and includes all the Nash equilibria. Further, the Nash equilibria all lie on the boundary of this polytope. We study the…

Computer Science and Game Theory · Computer Science 2020-12-07 Soham R. Phade , Venkat Anantharam

Nash equilibria provide a principled framework for modeling interactions in multi-agent decision-making and control. However, many equilibrium-seeking methods implicitly assume that each agent has access to the other agents' objectives and…

Computer Science and Game Theory · Computer Science 2026-03-19 Mahdis Rabbani , Navid Mojahed , Shima Nazari

Nash equilibrium (NE) is a central concept in game theory. Here we prove formally a published theorem on existence of an NE in two proof assistants, Coq and Isabelle: starting from a game with finitely many outcomes, one may derive a game…

Computer Science and Game Theory · Computer Science 2017-09-08 Stéphane Le Roux , Érik Martin-Dorel , Jan-Georg Smaus

We show that for any $\epsilon>0$, as the number of agents gets large, the share of games that admit a pure $\epsilon$-equilibrium converges to 1. Our result holds even for pure $\epsilon$-equilibrium in which all agents, except for at most…

Theoretical Economics · Economics 2025-05-28 Bary S. R. Pradelski , Bassel Tarbush

In this paper, we consider the competitive diffusion game, and study the existence of its pure-strategy Nash equilibrium when defined over general undirected networks. We first determine the set of pure-strategy Nash equilibria for two…

Computer Science and Game Theory · Computer Science 2015-06-09 Seyed Rasoul Etesami , Tamer Basar

A fundamental shortcoming of the concept of Nash equilibrium is its computational intractability: approximating Nash equilibria in normal-form games is PPAD-hard. In this paper, inspired by the ideas of smoothed analysis, we introduce a…

Computer Science and Game Theory · Computer Science 2024-07-23 Constantinos Daskalakis , Noah Golowich , Nika Haghtalab , Abhishek Shetty

Several notions of game enjoy a Nash-like notion of equilibrium without guarantee of existence. There are different ways of weakening a definition of Nash-like equilibrium in order to guarantee the existence of a weakened equilibrium.…

Computer Science and Game Theory · Computer Science 2007-12-11 Stéphane Le Roux

We analyze the performance of the best-response dynamic across all normal-form games using a random games approach. The playing sequence -- the order in which players update their actions -- is essentially irrelevant in determining whether…

Theoretical Economics · Economics 2022-11-18 Torsten Heinrich , Yoojin Jang , Luca Mungo , Marco Pangallo , Alex Scott , Bassel Tarbush , Samuel Wiese

We present efficient approximation algorithms for finding Nash equilibria in anonymous games, that is, games in which the players utilities, though different, do not differentiate between other players. Our results pertain to such games…

Computer Science and Game Theory · Computer Science 2007-10-31 Constantinos Daskalakis , Christos Papadimitriou

We consider a 3-player game in the normal form, in which each player has two actions. We assume that the game is symmetric and repeated infinitely many times. At each stage players make their choices knowing only the average payoffs from…

Optimization and Control · Mathematics 2018-05-16 Tadeusz Kufel , Sławomir Plaskacz , Joanna Zwierzchowska

Recently, a new model extending the standard replicator equation to a finite set of players connected on an arbitrary graph was developed in evolutionary game dynamics. The players are interpreted as subpopulations of multipopulations…

Computer Science and Game Theory · Computer Science 2021-11-16 Jean Carlo Moraes

We prove some regularity properties (convexity, closedness, compactness and preservation of upper hemicontinuity) for distribution and regular conditional distribution of correspondences under the nowhere equivalence condition. We show the…

Probability · Mathematics 2017-12-07 Wei He , Yeneng Sun

In recent and past works, convexity is usually assumed on each individual part of the action functional in order to demonstrate the existence and uniqueness of a Nash equilibrium on some interval [0, T] (this meant that each hessian was…

Optimization and Control · Mathematics 2022-10-20 Daniel Block , Moises Reyes Rivas

We analyse the computational complexity of finding Nash equilibria in simple stochastic multiplayer games. We show that restricting the search space to equilibria whose payoffs fall into a certain interval may lead to undecidability. In…

Computer Science and Game Theory · Computer Science 2010-06-24 Michael Ummels , Dominik Wojtczak

The Nash Equilibrium is a much discussed, deceptively complex, method for the analysis of non-cooperative games. If one reads many of the commonly available definitions the description of the Nash Equilibrium is deceptively simple in…

Computer Science and Game Theory · Computer Science 2007-07-09 Philip V. Fellman