activity
20042026
most citedReachability in Two-Clock Timed Automata is PSPACE-complete

27 citations · 187 across the 36 of their papers we have counts for

collaborators

48 papers

cs.GT2026

Constant Inapproximability for Fisher Markets

Argyrios Deligkas, John Fearnley, Alexandros Hollender +1

We study the problem of computing approximate market equilibria in Fisher markets with separable piecewise-linear concave (SPLC) utility functions. In this setting, the problem was…

cs.GT2026

Fisher Markets with Approximately Optimal Bundles and the Need for a PCP Theorem for PPAD

Argyrios Deligkas, John Fearnley, Alexandros Hollender +1

We study the problem of computing a competitive equilibrium with approximately optimal bundles in Fisher markets with separable piecewise-linear concave (SPLC) utility functions, m…

cs.CC2024

Super Unique Tarski is in UEOPL

John Fearnley, Rahul Savani

We define the Super-Unique-Tarski problem, which is a Tarski instance in which all slices are required to have a unique fixed point. We show that Super-Unique-Tarski lies in UEOPL…

cs.CC2024

Monotone Contractions

Eleni Batziou, John Fearnley, Spencer Gordon +2

We study functions that are both monotone and contracting, and we consider the problem of finding an -approximate fixed point of $f…

cs.CC2024

Two Choices are Enough for P-LCPs, USOs, and Colorful Tangents

Michaela Borzechowski, John Fearnley, Spencer Gordon +3

We provide polynomial-time reductions between three search problems from three distinct areas: the P-matrix linear complementarity problem (P-LCP), finding the sink of a unique sin…

cs.CC2023

The Complexity of Computing KKT Solutions of Quadratic Programs

John Fearnley, Paul W. Goldberg, Alexandros Hollender +1

It is well known that solving a (non-convex) quadratic program is NP-hard. We show that the problem remains hard even if we are only looking for a Karush-Kuhn-Tucker (KKT) point, i…