On Non-Monotone Variational Inequalities
Sina Arefizadeh, Angelia Nedić
TL;DR
This work addresses non-monotone variational inequalities by deriving sufficient conditions for the existence of solutions through inverse mapping theory and degree theory. It develops results for both unconstrained problems with differentiable mappings and constrained problems via the natural and normal mappings, Clark's inverse mapping theorem, and degree-theoretic arguments, including near-$\xi$-monotone mappings. The paper also establishes the existence of Minty solutions and proves subsequential convergence of the Korpelevich and Popov methods under Minty-solution assumptions, extending classical VI theory beyond monotone cases. Overall, it provides rigorous existence conditions and convergent algorithms for non-monotone VIs with practical implications for applications where monotonicity fails.
Abstract
In this paper, we provide some sufficient conditions for the existence of solutions to non-monotone Variational Inequalities (VIs) based on inverse mapping theory and degree theory. We have obtained several applicable sufficient conditions for this problem and have introduced a sufficient condition for the existence of a Minty solution. We have shown that the Korpelevich and Popov methods converge to a solution of a non-monotone VI, provided that a Minty solution exists.
