Saar Cohen

Positions

1. 2026 – present

   Postdoctoral Research Associate

   Department of Computer Science, University of Oxford

   Hosted by Prof. Michael Wooldridge.

Education

1. 2021 – 2025

   Ph.D. in Computer Science

   Bar-Ilan University

   Thesis: “Coalition Formation in Sequential Decision-Making under Uncertainty”. Advisor: Prof. Noa Agmon. Member of the SMART research group.

2. 2018 – 2021

   M.Sc. in Computer Science

   Bar-Ilan University

   Thesis: “Spatial Consensus Prevention in Robotic Swarms”, on influencing flocking agents by inserting diverting agents into the swarm to bring them to disagreement. Advisor: Prof. Noa Agmon.

3. 2013 – 2017

   B.Sc. in Mathematics

   Tel Aviv University

   With a specialization in Computer Science.

Publications

Conference papers 18

1. Gabriele La Malfa, Emanuele La Malfa, Saar Cohen, Jie M. Zhang, Michael Luck, Michael Wooldridge, and Elizabeth Black

   The Attacker in the Mirror: Breaking Self-Consistency in Safety via Anchored Bipolicy Self-PlayNeurIPS 2026 (to appear) · Oral

2. Saar Cohen

   Delayed Assignments in Online Non-Centroid Clustering with Stochastic ArrivalsAAMAS 2026 · Oral

3. Saar Cohen

   Offline Learning of Nash Stable Coalition Structures with Possibly Overlapping CoalitionsAAMAS 2026 · Oral

4. Saar Cohen, Noa Agmon, and Uri Shaham

   Convexified Message-Passing Graph Neural NetworksAISTATS 2026 · Poster

5. Saar Cohen and Noa Agmon

   Online Learning of Fair Coalition StructuresECAI 2025 · Oral

6. Saar Cohen and Noa Agmon

   Decentralized Online Learning by Selfish Agents in Coalition FormationIJCAI 2025 · Oral

7. Saar Cohen and Noa Agmon

   Egalitarianism in Online Coalition Formation (Extended Abstract)AAMAS 2025 · Poster

8. Saar Cohen and Noa Agmon

   Online Learning of Coalition Structures by Selfish AgentsAAAI 2025 · Oral

9. Saar Cohen and Noa Agmon

   Online Friends Partitioning under UncertaintyECAI 2024 · Spotlight

10. Saar Cohen and Noa Agmon

    Online Learning of Partitions in Additively Separable Hedonic GamesIJCAI 2024 · Oral

11. Saar Cohen and Noa Agmon

    Near-Optimal Online Resource Allocation in the Random-Order Model (Extended Abstract)AAMAS 2024 · Poster

12. Saar Cohen

    Coalition Formation in Sequential Decision-Making under Uncertainty (Doctoral Consortium)AAMAS 2023

13. Saar Cohen and Noa Agmon

    Online Coalitional Skill FormationAAMAS 2023 · Oral

14. Saar Cohen and Noa Agmon

    Complexity of Probabilistic Inference in Random Dichotomous Hedonic GamesAAAI 2023 · Poster

15. Saar Cohen and Noa Agmon

    Optimizing Multi-Agent Coordination via Hierarchical Graph Probabilistic Recursive ReasoningAAMAS 2022 · Oral (online)

16. Saar Cohen and Noa Agmon

    Convexified Graph Neural Networks for Distributed Control in Robotic SwarmsIJCAI 2021 · Oral (online)

17. Saar Cohen and Noa Agmon

    On the (Im)possibility of Leading a Swarm to a Desired Consensus in Static and Dynamic SettingsDARS/SWARM 2021

18. Saar Cohen and Noa Agmon

    Spatial Consensus-Prevention in Robotic SwarmsAAMAS 2021 · Oral (online)

Journal articles & surveys 3

1. Saar Cohen and Noa Agmon

   Fairness and Efficiency in Online Coalition Formation with Partial InformationJAIR 2026 (accepted with minor revisions)

2. Saar Cohen and Noa Agmon

   Stability-Accuracy Tradeoffs in Decentralized Online Learning of Coalition Structures by Selfish AgentsJAIR 2026

3. Saar Cohen and Noa Agmon

   Recent Advances in Formations of Multiple RobotsCurrent Robotics Reports · Survey

Working papers 4

1. Emanuele La Malfa^*, Saar Cohen^*, Gabriele La Malfa^*, Mickel Liu, Christian Schroeder de Witt, Natasha Jaques, and Michael J. Wooldridge

   Reflections and Fragments: Securing LLMs Against Sequential Mosaic AttacksarXiv 2610.05346. ^*These authors contributed equally to this work.Emanuele La Malfa, Saar Cohen and Gabriele La Malfa contributed equally to this work.

2. Saar Cohen, Nicholas Teh, and Michael Wooldridge

   Online Fair Division Against an Oblivious AdversaryarXiv 2609.28333

3. Nicholas Teh, Saar Cohen, Karen Frilya Celine, Benjamin Yu, and Michael J. Wooldridge

   Online House Allocation with SubsidyarXiv 2609.29691

4. Saar Cohen, Nicholas Teh, Paul W. Goldberg, and Michael J. Wooldridge

   Online Fair Division with Budget ConstraintsarXiv 2607.23310

Under review / revision 2

1. Saar Cohen and Noa Agmon

   Egalitarian Welfare Maximization in Online Coalition FormationUnder review

2. Saar Cohen and Noa Agmon

   Near-Optimal Online Resource Allocation in the Random-Order ModelUnder review

Awards & scholarships

1. 2025

   IAAI Best PhD Thesis Award

2. 2024

   CS@BIU Nadav Scholarship for Excellent PhD Students

3. 2023

   The President’s Scholarship Program for Outstanding Doctoral Students

   On behalf of the president of Bar-Ilan University

4. 2022

   CS@BIU Nadav Scholarship for Excellent M.Sc. Students

Service

Organization

1. 2026

   Organizer, 3rd Workshop on Social Choice and Learning Algorithms (SCaLA’26)

   Held at IJCAI’26, Bremen, Germany

Reviewing

1. 2026

   Program Committee

   AAAI’26, AAMAS’26

2. 2025

   Program Committee

   AAAI’25, AAMAS’25 (Distinguished), IJCAI’25, ECAI’25

3. 2024

   Program Committee

   AAAI’24, IJCAI’24

4. 2024

   Reviewer

   ECAI’24

5. 2023

   Program Committee

   AAAI’23, IJCAI’23 (Distinguished)

6. 2023

   Reviewer

   ICRA’23, ECAI’23

7. 2022

   Reviewer

   AAMAS’22, IEEE Transactions on Robotics (T-RO)

Teaching

1. 2023 – 2025

   Teaching Assistant

   Department of Computer Science, Bar-Ilan University

   • Discrete Structures (Fall 2023, Fall 2024); lead TA in Fall 2024; prepared the presentations for all recitations
   • Machine Learning (Spring 2024, Spring 2025); lead TA in Spring 2025