activity
20242026
collaborators

9 papers

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.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.CC2026

Pizza Sharing is PPA-hard

Argyrios Deligkas, John Fearnley, Themistoklis Melissourgos

We study the computational complexity of finding a solution for the straight-cut and square-cut pizza sharing problems. We show that computing an -approximate solution…

cs.CC2025

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…

cs.CC2025

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

Constant Inapproximability for PPA

Argyrios Deligkas, John Fearnley, Alexandros Hollender +1

In the -Consensus-Halving problem, we are given probability measures on the interval , and the goal is to partition into two parts…