Zhihao Gu

collaborators

Showing math.OCShow all

4 papers · 1 filter

math.OC2026

An $Ω (κ_{y}^{8} ε^{- 6})$ Lower Bound for Stochastic NC-SC Bilevel Optimization with First-order Oracles

Zhihao Gu, Qilong Wu, Junchi Yang

We study the oracle complexity of finding $ε$ -stationary points of smooth bilevel optimization problems with a nonconvex upper-level objective and a strongly convex lower-level pro…

math.OC2026

Lower Bounds for Nonconvex-Concave Minimax Optimization

Qilong Wu, Zhihao Gu, Junchi Yang

We study lower bounds on the first-order oracle complexity of smooth nonconvex-concave minimax optimization. We consider objectives $f$ that are jointly $L$ -smooth in the primal an…

math.OC2026

SGHA: A Single-Loop Fully First-Order Algorithm for Nonconvex-Strongly-Convex Bilevel Optimization

Zhihao Gu, Qilong Wu, Junchi Yang

In this work, we study the oracle complexity of finding an $ε$ -stationary point for nonconvex-strongly-convex (NC-SC) bilevel optimization using only first-order oracles. Existing…

math.OC2024

Zeroth-Order Stochastic Mirror Descent Algorithms for Minimax Excess Risk Optimization

Zhihao Gu, Zi Xu

The minimax excess risk optimization (MERO) problem is a new variation of the traditional distributionally robust optimization (DRO) problem, which achieves uniformly low regret ac…

An Ω(κy8​ε−6) Lower Bound for Stochastic NC-SC Bilevel Optimization with First-order Oracles

Lower Bounds for Nonconvex-Concave Minimax Optimization

SGHA: A Single-Loop Fully First-Order Algorithm for Nonconvex-Strongly-Convex Bilevel Optimization

Zeroth-Order Stochastic Mirror Descent Algorithms for Minimax Excess Risk Optimization

An $Ω (κ_{y}^{8} ε^{- 6})$ Lower Bound for Stochastic NC-SC Bilevel Optimization with First-order Oracles