collaborators

6 papers

cs.LG2026

How Token Influence Decays with Distance: A Green-Function View of Trained Language Models

Matthias Brändel, Stephan Köhler, Oliver Rheinbach

We study how the next-token prediction of an autoregressive Transformer language model changes under small perturbations of earlier input token embeddings. Motivated by operator le…

cs.LG2026

Overlapping Schwarz Attention: Hierarchical Attention via Domain Decomposition

Stephan Köhler, Oliver Rheinbach

We propose a hierarchical attention mechanism based on two-level overlapping Schwarz domain decomposition. The method is motivated by domain decomposition methods in partial differ…

math.NA2026

Overlapping Schwarz Preconditioners for Pose-Graph SLAM in Robotics

Stephan Köhler, Oliver Rheinbach, Yue Xiang Tee +1

We investigate scalable two-level overlapping Schwarz domain decomposition methods with energy-minimizing coarse spaces of GDSW type (Generalized Dryja--Smith--Widlund type) as pre…

math.NA2026

Four-Level Overlapping Schwarz as Multigrid Coarse Solver for Incompressible Non-Newtonian Flow in Complex Geometries

Stephan Köhler, Oliver Rheinbach

For complex geometries, the coarse problem of geometric multigrid can be too large to be solved by a direct solver. Here, we report on the use of domain decomposition applied to th…

math.NA2026

Monolithic Multi-level Overlapping Schwarz Solvers for Fluid Problems

Stephan Köhler, Oliver Rheinbach

Additive overlapping Schwarz Methods are iterative methods of the domain decomposition type for the solution of partial differential equations. Numerical and parallel scalability o…

math.NA2025

Combining Nonlinear FETI-DP Methods and Quasi-Newton Methods using an SQP Approach

Stephan Köhler, Oliver Rheinbach

The combination of nonlinear FETI-DP (Dual Primal Finite Element Tearing and Interconnecting) and Quasi-Newton methods using a sequential quadratic programming (SQP) approach is co…