collaborators

12 papers

cs.CL2026

APM: Evaluating Style Personalization in LLMs with Arbitrary Preference Mappings

Philipp Spohn, Leander Girrbach, Zeynep Akata

Typical LLM responses tend to follow a default style, even though users often have distinct preferences regarding tone, verbosity, and formality that they do not explicitly state i…

cs.CV2026

Sparse Autoencoders are Topic Models

Leander Girrbach, Zeynep Akata

Sparse autoencoders (SAEs) are used to analyze embeddings, but their role and practical value are debated. We propose a new perspective on SAEs by demonstrating that they can be na…

cs.AI2026

Do LLMs Experience an Internal Polylogue? Investigating Reasoning through the Lens of Personas

Nils A. Herrmann, Leander Girrbach, Kirill Bykov +1

Recent work shows that large language models (LLMs) encode behavioral traits ("personas") as linear directions in activation space, often called "persona vectors". Prior work has u…

cs.CL2026

A Systematic Study of In-the-Wild Model Merging for Large Language Models

Oğuz Kağan Hitit, Leander Girrbach, Zeynep Akata

Model merging combines multiple fine-tuned checkpoints into a single model without additional training, offering an attractive approach to reusing models and efficiently improving…

cs.CV2026

Person-Centric Annotations of LAION-400M: Auditing Bias and Its Transfer to Models

Leander Girrbach, Stephan Alaniz, Genevieve Smith +2

Vision-language models trained on large-scale multimodal datasets show strong demographic biases, but the role of training data in producing these biases remains unclear. A major b…

cs.AI2026

Are Reasoning LLMs Robust to Interventions on Their Chain-of-Thought?

Alexander von Recum, Leander Girrbach, Zeynep Akata

Reasoning LLMs (RLLMs) generate step-by-step chains of thought (CoTs) before giving an answer, which improves performance on complex tasks and makes reasoning more transparent. But…