8 papers
Minimisation of Quasar-Convex Functions Using Random Zeroth-Order Oracles
Amir Ali Farzin, Yuen-Man Pun, Philipp Braun +1
This paper explores the performance of a random Gaussian smoothing zeroth-order (ZO) scheme for minimising quasar-convex (QC) and strongly quasar-convex (SQC) functions in both unc…
Solving the Offline and Online Min-Max Problem of Non-smooth Submodular-Concave Functions: A Zeroth-Order Approach
Amir Ali Farzin, Yuen-Man Pun, Philipp Braun +2
We consider max-min and min-max problems with objective functions that are possibly non-smooth, submodular with respect to the minimiser and concave with respect to the maximiser.…
Online Sketched Newton-Raphson
Jean-Luc Lupien, Yuen-Man Pun, Youssef Diouane +2
In online convex optimization (OCO), a decision-maker is confronted with an unknown environment and seeks to play an optimal sequence of decisions on a short time-scale using only…
Taking the Road Less Scheduled with Adaptive Polyak Steps
Dimitris Oikonomou, Matthew Buchholz, Yuen-Man Pun +2
Schedule-Free SGD, proposed in [Defazio et al., 2024], achieves optimal convergence rates without requiring the training horizon in advance, by replacing learning rate schedules wi…
On the Stability Connection Between Discrete-Time Algorithms and Their Resolution ODEs: Applications to Min-Max Optimisation
Amir Ali Farzin, Yuen-Man Pun, Philipp Braun +1
This work establishes a rigorous connection between stability properties of discrete-time algorithms (DTAs) and corresponding continuous-time dynamical systems derived through $ O(…
Minimisation of Submodular Functions Using Gaussian Zeroth-Order Random Oracles
Amir Ali Farzin, Yuen-Man Pun, Philipp Braun +2
We consider the minimisation problem of submodular functions and investigate the application of a zeroth-order method to this problem. The method is based on exploiting a Gaussian…