# Complexity Analysis of a Trust Funnel Algorithm for Equality Constrained Optimization

arXiv: https://arxiv.org/abs/1707.00337 · HTML: https://mlsanity.com/paper/1707.00337/

## Key facts

- Cited by 3 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 2 Jul 2017.

## Built on by (most cited first, 3 of 3)

- [A Newton-CG based augmented Lagrangian method for finding a second-order stationary point of nonconvex equality constrained optimization with complexity guarantees](https://mlsanity.com/paper/2301.03139/) (2023)
- [A Newton-CG based barrier-augmented Lagrangian method for general nonconvex conic optimization](https://mlsanity.com/paper/2301.04204/) (2023)
- [TR-SSQP: A Trust-Region Method for Constrained Stochastic Optimization under Heavy-Tailed Noise](https://mlsanity.com/paper/2609.30732/) (2026)

## Abstract (arXiv)

A method is proposed for solving equality constrained nonlinear optimization problems involving twice continuously differentiable functions. The method employs a trust funnel approach consisting of two phases: a first phase to locate an ε-feasible point and a second phase to seek optimality while maintaining at least ε-feasibility. A two-phase approach of this kind based on a cubic regularization methodology was recently proposed along with a supporting worst-case iteration complexity analysis. Unfortunately, however, in that approach, the objective function is completely ignored in the first phase when ε-feasibility is sought. The main contribution of the method proposed in this paper is that the same worst-case iteration complexity is achieved, but with a first phase that also accounts for improvements in the objective function. As such, the method typically requires fewer iterations in the second phase, as the results of numerical experiments demonstrate.