8 papers
Proximal basin hopping: global optimization with guarantees
Guillaume Lauga, Cesare Molinari, Samuel Vaiter
Global optimization is a challenging problem, with plenty of algorithms displaying empirical success, but scarce theoretical backing. In this work, we propose a new theoretical fra…
Characterizations of inexact proximal operators
Guillaume Lauga, Samuel Vaiter
Proximal operators are now ubiquitous in non-smooth optimization. Since their introduction in the seminal work of Moreau, many papers have shown their effectiveness on a wide varie…
A block-coordinate descent framework for non-convex composite optimization. Application to sparse precision matrix estimation
Guillaume Lauga
Block-coordinate descent (BCD) is the method of choice to solve numerous large scale optimization problems, however their theoretical study for non-convex optimization, has receive…
A flexible block-coordinate forward-backward algorithm for non-smooth and non-convex optimization
Luis Briceño-Arias, Paulo Gonçalves, Guillaume Lauga +2
Block coordinate descent (BCD) methods are prevalent in large scale optimization problems due to the low memory and computational costs per iteration, the predisposition to paralle…
A multilevel approach to accelerate the training of Transformers
Guillaume Lauga, Maël Chaumette, Edgar Desainte-Maréville +2
In this article, we investigate the potential of multilevel approaches to accelerate the training of transformer architectures. Using an ordinary differential equation (ODE) interp…
A multilevel framework for accelerating uSARA in radio-interferometric imaging
Guillaume Lauga, Audrey Repetti, Elisa Riccietti +3
This paper presents a multilevel algorithm specifically designed for radio-interferometric imaging in astronomy. The proposed algorithm is used to solve the uSARA (unconstrained Sp…
IML FISTA: A Multilevel Framework for Inexact and Inertial Forward-Backward. Application to Image Restoration
Guillaume Lauga, Elisa Riccietti, Nelly Pustelnik +1
This paper presents a multilevel framework for inertial and inexact proximal algorithms, that encompasses multilevel versions of classical algorithms such as forward-backward and F…
Multilevel fista for image restoration
Guillaume Lauga, Elisa Riccietti, Nelly Pustelnik +1
This paper presents a multilevel FISTA algorithm, based on the use of the Moreau envelope to build the correction brought by the coarse models, which is easy to compute when the ex…