During his PhD studies, Sebastian researched a variety of social choice mechanisms.

Social choice mechanisms are schemes for a wide array of aggregate decision-making problems such as voting, allocation or coalition formation. Sebastian analysed multiple aspects of the well-known Random Serial Dictatorship mechanism across different settings and proposed new mechanisms in the sphere of matching.

These contributions shine a new light onto classical mechanisms and provide new mechanisms alike as well as extend our knowledge on the boundary of possible approximation guarantees.

The PhD study was completed at the Department of Computer Science, Faculty of Natural Sciences, Aarhus University.

This summary was prepared by the PhD student.

Time: Wednesday, 18^th March 2026 at 9:00 am.
Place: Building 5342, room 333 Ada, Department of Computer Science, Aarhus University, Åbogade 34, 8200 Aarhus N.
Title of PhD thesis: A Tale of Social Choice Mechanisms
Contact information: Sebastian Homrighausen, e-mail: homrighausen@cs.au.dk, tel.: +45 27281332
Members of the assessment committee:
Professor Dimitris Fotakis, School of Electrical and Computer Engineering, National Technical University of Athens, Greece
Professor Martin Hoefer, Department of Computer Science, RWTH Aachen University, Germany
Professor Ira Assent (chair), Department of Computer Science, Aarhus University, Denmark
Main supervisor: Professor Ioannis Caragiannis, Department of Computer Science, Aarhus University, Denmark
Language: The PhD dissertation will be defended in English

The defence is public.
The PhD thesis is available for reading at the Graduate School of Natural Sciences/GSNS, Ny Munkegade 120, building 1521, 8000 Aarhus C