Hot off the Press: Improved Runtime Guarantees for the SPEA2 Multi-Objective Optimizer

Provable Speedups From Dynamic Population Sizes in Evolutionary Algorithms for Multiobjective Optimization

This paper introduces the bi-objective problem class CLIMB and analyzes the runtime of GSEMO and the widely used NSGA-II on this problem, and proves that GSEMO and NSGA-II-DYN, a version of NSGA-II with dynamic population sizes, can find the Pareto front of CLIMB in expected fitness evaluations.

The Zero Regrets Algorithm: Optimizing over Pure Nash Equilibria via Integer Programming

MLDGWO: a grey wolf optimizer with momentum, leader adjustment, and differential perturbation for global optimization problems

Applied to five engineering optimization problems, modified momentum–leader–differential grey wolf optimizer consistently achieves the lowest objective values, while analytically proving its ability to navigate heavily penalized boundaries and satisfy all constraints.

Insights from Multi-tasking the EAX Algorithm for the Travelling Salesperson Problem

Evolutionary multitasking allows several related problems to be solved in a single run of an algorithm. In this paper, we investigate integrating evolutionary multitasking with Edge Assembly Crossover (MT-EAX) to solve the classical Travelling Salesperson Problem (TSP). To fairly compare MT-EAX against standard EAX under strict compute budgets, we evaluate three scaling methods: generation scaling, population scaling, and balanced scaling. Our results show that generationally scaled MT-EAX is highly effective compute-wise in the early stages of the search, saving $60\%$ to $90\%$ of compute for equal or better solution quality. We observe that instance geometry has a significant impact, with clustered, normally distributed instances securing larger improvements than uniformly distributed ones. However, when scaling by population or utilising explicit solution transfer, the results are negative due to population starvation and incompatible cross-instance parent selection. We demonstrate that the advantage of MT-EAX derives from increased diversity through parallel search in early generations, which can be successfully preserved using a decoupled configuration to often strictly outperform or match standard EAX performance at final convergence.

Parallelizable Gradient-Based Optimization For Multi-Objective MaxCut

Multi-objective combinatorial optimization arises in a wide range of problems and applications, including the canonical multi-objective MaxCut problem. Differentiable single-instance quadratic methods have recently achieved remarkable performance in single-objective combinatorial optimization. In this paper, we develop a differentiable framework for multi-objective MaxCut by combining an adjacency-based quadratic formulation with linear scalarization, thereby reducing the problem to a preference-conditioned single-objective signed-weight MaxCut problem. Theoretically, we characterize the stationary points of the resulting signed-weight formulation and show how they induce preference-conditioned fixed points on the Pareto front. Computationally, unlike conventional heuristics and branch-and-bound methods, our approach is GPU-parallelizable and can therefore benefit from substantial performance speedups. We term our algorithm Multi-objective QUadratic Combinatorial Optimization (MO-QUCO) and its parallelized variant pMO-QUCO. Empirically, across different multi-layered (and weight distributions) graphs, we show that both our CPU-only and GPU-based algorithms outperform SOTA exact and heuristic methods in terms of wall-clock runtime and objective quality. Despite operating under different computational settings, MO-QUCO also outperforms the SOTA quantum method.

Beyond Scalar Fitness: Behavioural Feedback for LLM-Driven Metaheuristic Evolution

It is found that neutral framing of behavioural features, reporting the feature value without prescriptive advice, consistently outperforms the prescriptive variants, and that prescriptive feedback steers the median feature value in the advised direction in only 37% of cases despite empirically grounded advice.