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Christian Kümmerle

7 accepted papers

2025

Q3R: Quadratic Reweighted Rank Regularizer for Effective Low-Rank Training

NeurIPS 2025poster

Parameter-efficient training, based on low-rank optimization, has become a highly successful tool for fine-tuning large deep-learning models. However, these methods fail at low-rank pre-training tasks where maintaining the low-rank structure and the objective remains a challenging task. We propose t…

Cited by 0SourceScholar
2024

Sample-Efficient Geometry Reconstruction from Euclidean Distances using Non-Convex Optimization

NeurIPS 2024poster

The problem of finding suitable point embedding or geometric configurations given only Euclidean distance information of point pairs arises both as a core task and as a sub-problem in a variety of machine learning applications. In this paper, we aim to solve this problem given a minimal number of di…

2023

On the Convergence of IRLS and Its Variants in Outlier-Robust Estimation

CVPR 2023highlight

Outlier-robust estimation involves estimating some parameters (e.g., 3D rotations) from data samples in the presence of outliers, and is typically formulated as a non-convex and non-smooth problem. For this problem, the classical method called iteratively reweighted least-squares (IRLS) and its vari…

2023

Recovering Simultaneously Structured Data via Non-Convex Iteratively Reweighted Least Squares

NeurIPS 2023poster

We propose a new algorithm for the problem of recovering data that adheres to multiple, heterogenous low-dimensional structures from linear observations. Focussing on data matrices that are simultaneously row-sparse and low-rank, we propose and analyze an iteratively reweighted least squares (IRLS)…

2022

Global Linear and Local Superlinear Convergence of IRLS for Non-Smooth Robust Regression

NeurIPS 2022accept

We advance both the theory and practice of robust $\ell_p$-quasinorm regression for $p \in (0,1]$ by using novel variants of iteratively reweighted least-squares (IRLS) to solve the underlying non-smooth problem. In the convex case, $p=1$, we prove that this IRLS variant converges globally at a line…

2021

A Scalable Second Order Method for Ill-Conditioned Matrix Completion from Few Samples

ICML 2021spotlight

We propose an iterative algorithm for low-rank matrix completion with that can be interpreted as an iteratively reweighted least squares (IRLS) algorithm, a saddle-escaping smoothing Newton method or a variable metric proximal gradient method applied to a non-convex rank surrogate. It combines the f…

2021

Iteratively Reweighted Least Squares for Basis Pursuit with Global Linear Convergence Rate

NeurIPS 2021spotlight

The recovery of sparse data is at the core of many applications in machine learning and signal processing. While such problems can be tackled using $\ell_1$-regularization as in the LASSO estimator and in the Basis Pursuit approach, specialized algorithms are typically required to solve the correspo…

Cited by 22SourcePDFScholar