Hasso-Plattner-Institut
Prof. Dr. Tobias Friedrich
 

Dr. Pascal Lenzner

Chair for Algorithm Engineering
Hasso Plattner Institute

Office: K-2.17
Tel.: +49 331 5509-418

E-Mail: Pascal.Lenzner(at)hpi.de

Research Interests

My research interests lie in the intersection of algorithms, game theory and artificial intelligence.
I'm especially interested in:

  • Algorithmic Game Theory, in particular the impact of selfish behavior in optimization problems
  • Foundations of Artificial Intelligence, in particular strategic behavior in multi-agent systems
  • Network Science, in particular modeling and analyzing network creation by selfish agents
  • Network Design and algorithmic problems on graphs in general
  • Game-theoretic analysis of models from Sociology (e.g. Schelling's segregation model) and Economics (e.g. the Hotelling-Downs model)

News

Short CV

Education:  

2014: PhD degree (Dr. rer. nat.) in computer science from Humboldt-University Berlin, Germany

2009: Diploma degree in computer science (Dipl.-Inf.) from Friedrich-Schiller-University Jena, Germany

2007 - 2009: Studies in theoretical computer science at ETH Zürich, Switzerland

2003 - 2007: Studies in computer science at Friedrich-Schiller-University Jena, Germany 

 

Positions:

Starting 10/2020: Associated Member in the Research Unit Algorithms, Dynamics and Information Flow in Networks (ADYN) funded by the German Science Foundation

Starting 08/2020: Principal Investigator for the project Geometric Selfish Network Creation (GEONET) funded by the German Science Foundation

Starting 10/2015: PostDoc in the Algorithm Engineering Group at Hasso-Plattner-Institute Potsdam, Germany

2014 - 2015: PostDoc in the Complexity and the Theoretical Computer Science I groups at Friedrich-Schiller-University Jena, Germany

2014: PostDoc in the Algorithms & Complexity Group at Humboldt-University Berlin, Germany

2009 - 2014: PhD Student in the Algorithms & Complexity Group at Humboldt-University Berlin, Germany

Publications

[ 2024 ] [ 2023 ] [ 2022 ] [ 2021 ] [ 2020 ] [ 2019 ] [ 2018 ] [ 2017 ] [ 2016 ] [ 2015 ] [ 2014 ] [ 2013 ] [ 2012 ] [ 2011 ] [ 2010 ]

2024 [ nach oben ]

  • Sauer, Pascal; Cseh, Ágnes; Lenzner, Pascal Improving ranking quality and fairness in Swiss-system chess tournamentsJournal of Quantitative Analysis in Sports 2024
     
  • Bilò, Davide; Friedrich, Tobias; Lenzner, Pascal; Melnichenko, Anna Geometric Network Creation GamesSIAM Journal on Discrete Mathematics 2024: 277–315
     

2023 [ nach oben ]

  • Social Distancing Network... - Download
    Friedrich, Tobias; Gawendowicz, Hans; Lenzner, Pascal; Melnichenko, Anna Social Distancing Network CreationAlgorithmica 2023
     
  • Single-Peaked Jump Schell... - Download
    Friedrich, Tobias; Lenzner, Pascal; Molitor, Louise; Seifert, Lars Single-Peaked Jump Schelling GamesInternational Symposium on Algorithmic Game Theory (SAGT) 2023
     
  • Strategic Facility Locati... - Download
    Krogmann, Simon; Lenzner, Pascal; Skopalik, Alexander Strategic Facility Location with Clients that Minimize Total Waiting TimeConference on Artificial Intelligence (AAAI) 2023: 5714–5721
     
  • The Swiss Gambit - Download
    Cseh, Ágnes; Führlich, Pascal; Lenzner, Pascal The Swiss GambitAutonomous Agents and Multi-Agent Systems (AAMAS) 2023
     
  • Equilibria and Convergenc... - Download
    Bertschinger, Nils; Hoefer, Martin; Krogmann, Simon; Lenzner, Pascal; Schuldenzucker, Steffen; Wilhelmi, Lisa Equilibria and Convergence in Fire Sale GamesAutonomous Agents and Multiagent Systems (AAMAS) 2023: 215–223
     
  • Single-Peaked Jump Schell... - Download
    Friedrich, Tobias; Lenzner, Pascal; Molitor, Louise; Seifert, Lars Single-Peaked Jump Schelling GamesAutonomous Agents and Multiagent Systems (AAMAS) 2023: 2899–2901
     
  • Applying Skeletons to Spe... - Download
    Khomutovskiy, Ivan; Dunker, Rebekka; Dierking, Jessica; Egbert, Julian; Helms, Christian; Schöllkopf, Finn; Casel, Katrin; Fischbeck, Philipp; Friedrich, Tobias; Isaac, Davis; Krogmann, Simon; Lenzner, Pascal Applying Skeletons to Speed Up the Arc-Flags Routing AlgorithmSIAM Symposium on Algorithm Engineering and Experiments (ALENEX) 2023: 110–122
     
  • Temporal Network Creation... - Download
    Bilò, Davide; Cohen, Sarel; Friedrich, Tobias; Gawendowicz, Hans; Klodt, Nicolas; Lenzner, Pascal; Skretas, George Temporal Network Creation GamesInternational Joint Conference on Artificial Intelligence (IJCAI) 2023: 2511–2519
     
  • Schelling Games with Cont... - Download
    Bilò, Davide; Bilò, Vittorio; Döring, Michelle; Lenzner, Pascal; Molitor, Louise; Schmidt, Jonas Schelling Games with Continuous TypesInternational Joint Conference on Artificial Intelligence (IJCAI) 2023: 2520–2527
     
  • Strategic Resource Select... - Download
    Gadea Harder, Jonathan; Krogmann, Simon; Lenzner, Pascal; Skopalik, Alexander Strategic Resource Selection with Homophilic AgentsInternational Joint Conference on Artificial Intelligence (IJCAI) 2023: 2701–2709
     
  • The Impact of Cooperation... - Download
    Friedrich, Tobias; Gawendowicz, Hans; Lenzner, Pascal; Zahn, Arthur The Impact of Cooperation in Bilateral Network CreationACM Symposium on Principles of Distributed Computing (PODC) 2023
     

2022 [ nach oben ]

  • Topological Influence and... - Download
    Bilò, Davide; Bilò, Vittorio; Lenzner, Pascal; Molitor, Louise Topological Influence and Locality in Swap Schelling GamesAutonomous Agents and Multi-Agent Systems (AGNT) 2022: 47
     
  • Asynchronous Opinion Dyna... - Download
    Berenbrink, Petra; Hoefer, Martin; Kaaser, Dominik; Lenzner, Pascal; Rau, Malin; Schmand, Daniel Asynchronous Opinion Dynamics in Social NetworksAutonomous Agents and Multi-Agent Systems (AAMAS) 2022: 109–117
     
  • Improving Ranking Quality... - Download
    Führlich, Pascal; Cseh, Ágnes; Lenzner, Pascal Improving Ranking Quality and Fairness in Swiss-System Chess TournamentsACM Conference on Economics and Computation (EC) 2022: 1101–1102
     
  • Social Distancing Network... - Download
    Friedrich, Tobias; Gawendowicz, Hans; Lenzner, Pascal; Melnichenko, Anna Social Distancing Network CreationInternational Colloquium on Automata, Languages and Programming (ICALP) 2022: 62:1–62:21
     
  • Tolerance is Necessary fo... - Download
    Bilò, Davide; Bilò, Vittorio; Lenzner, Pascal; Molitor, Louise Tolerance is Necessary for Stability: Single-Peaked Swap Schelling GamesInternational Joint Conference on Artificial Intelligence (IJCAI) 2022: 81–87
     
  • Network Creation with Hom... - Download
    Bullinger, Martin; Lenzner, Pascal; Melnichenko, Anna Network Creation with Homophilic AgentsInternational Joint Conference on Artificial Intelligence (IJCAI) 2022: 151–157
     

2021 [ nach oben ]

  • Selfish Creation of Socia... - Download
    Bilò, Davide; Friedrich, Tobias; Lenzner, Pascal; Lowski, Stefanie; Melnichenko, Anna Selfish Creation of Social NetworksConference on Artificial Intelligence (AAAI) 2021: 5185–5193
     
  • Two-Stage Facility Locati... - Download
    Krogmann, Simon; Lenzner, Pascal; Molitor, Louise; Skopalik, Alexander Two-Stage Facility Location Games with Strategic Clients and FacilitiesInternational Joint Conference on Artificial Intelligence (IJCAI) 2021: 292–298
     
  • Efficiency and Stability ... - Download
    Friedemann, Wilhelm; Friedrich, Tobias; Gawendowicz, Hans; Lenzner, Pascal; Melnichenko, Anna; Peters, Jannik; Stephan, Daniel; Vaichenker, Michael Efficiency and Stability in Euclidean Network DesignSymposium on Parallelism in Algorithms and Architectures (SPAA) 2021: 232–242
     

2020 [ nach oben ]

  • On the Tree Conjecture fo... - Download
    Bilò, Davide; Lenzner, Pascal On the Tree Conjecture for the Network Creation GameTheory of Computing Systems 2020: 422–443
     
  • A Strategic Routing Frame... - Download
    Bläsius, Thomas; Böther, Maximilian; Fischbeck, Philipp; Friedrich, Tobias; Gries, Alina; Hüffner, Falk; Kißig, Otto; Lenzner, Pascal; Molitor, Louise; Schiller, Leon; Wells, Armin; Wietheger, Simon A Strategic Routing Framework and Algorithms for Computing Alternative PathsAlgorithmic Approaches for Transportation Modelling, Optimization, and Systems (ATMOS) 2020: 10:1–10:14
     
  • Fair Tree Connection Game... - Download
    Bilò, Davide; Friedrich, Tobias; Lenzner, Pascal; Melnichenko, Anna; Molitor, Louise Fair Tree Connection Games with Topology-Dependent Edge CostFoundations of Software Technology and Theoretical Computer Science (FSTTCS) 2020: 15:1–15:15
     
  • Flow-Based Network Creati... - Download
    Echzell, Hagen; Friedrich, Tobias; Lenzner, Pascal; Melnichenko, Anna Flow-Based Network Creation GamesInternational Joint Conference on Artificial Intelligence (IJCAI) 2020: 139–145
     
  • Topological Influence and... - Download
    Bilò, Davide; Bilò, Vittorio; Lenzner, Pascal; Molitor, Louise Topological Influence and Locality in Swap Schelling GamesInternational Symposium on Mathematical Foundations of Computer Science (MFCS) 2020: 15:1–15:15
     

2019 [ nach oben ]

  • From Hotelling to Load Ba... - Download
    Feldotto, Matthias; Lenzner, Pascal; Molitor, Louise; Skopalik, Alexander From Hotelling to Load Balancing: Approximation and the Principle of Minimum DifferentiationAutonomous Agents and Multiagent Systems (AAMAS) 2019: 1949–1951
     
  • Geometric Network Creatio... - Download
    Bilò, Davide; Friedrich, Tobias; Lenzner, Pascal; Melnichenko, Anna Geometric Network Creation GamesSymposium on Parallelism in Algorithms and Architectures (SPAA) 2019: 323–332
     
  • Convergence and Hardness ... - Download
    Echzell, Hagen; Friedrich, Tobias; Lenzner, Pascal; Molitor, Louise; Pappik, Marcus; Schöne, Friedrich; Sommer, Fabian; Stangl, David Convergence and Hardness of Strategic Schelling SegregationWeb and Internet Economics (WINE) 2019: 156–170
     

2018 [ nach oben ]

  • Schelling Segregation wit... - Download
    Chauhan, Ankit; Lenzner, Pascal; Molitor, Louise Schelling Segregation with Strategic AgentsSymposium on Algorithmic Game Theory (SAGT) 2018
     
  • On the Tree Conjecture fo... - Download
    Bilò, Davide; Lenzner, Pascal On the Tree Conjecture for the Network Creation GameSymposium on the Theoretical Aspects of Computer Science (STACS) 2018: 14:1–14:15
     

2017 [ nach oben ]

  • Selfish Network Creation ... - Download
    Chauhan, Ankit; Lenzner, Pascal; Melnichenko, Anna; Molitor, Louise Selfish Network Creation with Non-Uniform Edge CostSymposium on Algorithmic Game Theory (SAGT) 2017: 160–172
     
  • Efficient Best Response C... - Download
    Friedrich, Tobias; Ihde, Sven; Keßler, Christoph; Lenzner, Pascal; Neubert, Stefan; Schumann, David Efficient Best Response Computation for Strategic Network Formation under AttackSymposium on Algorithmic Game Theory (SAGT) 2017: 199–211
     
  • Brief Announcement: Effic... - Download
    Friedrich, Tobias; Ihde, Sven; Keßler, Christoph; Lenzner, Pascal; Neubert, Stefan; Schumann, David Brief Announcement: Efficient Best Response Computation for Strategic Network Formation under AttackSymposium on Parallelism in Algorithms and Architectures (SPAA) 2017: 321–323
     

2016 [ nach oben ]

  • On Selfish Creation of Ro... - Download
    Chauhan, Ankit; Lenzner, Pascal; Melnichenko, Anna; Münn, Martin On Selfish Creation of Robust NetworksSymposium on Algorithmic Game Theory (SAGT) 2016: 141–152
     

2015 [ nach oben ]

  • Network Creation Games: T... - Download
    Cord-Landwehr, Andreas; Lenzner, Pascal Network Creation Games: Think Global - Act LocalMathematical Foundations of Computer Science (MFCS) 2015: 248–260
     

2014 [ nach oben ]

  • On selfish network creati... - Download
    Lenzner, Pascal On selfish network creationDoctoral Dissertation, Humboldt University of Berlin 2014
     

2013 [ nach oben ]

  • On Approximate Nash Equil... - Download
    Albers, Susanne; Lenzner, Pascal On Approximate Nash Equilibria in Network DesignInternet Mathematics 2013: 384–405
     
  • On dynamics in selfish ne... - Download
    Kawald, Bernd; Lenzner, Pascal On dynamics in selfish network creationSymposium on Parallelism in Algorithms and Architectures (SPAA) 2013: 83–92
     

2012 [ nach oben ]

  • Greedy Selfish Network Cr... - Download
    Lenzner, Pascal Greedy Selfish Network CreationWeb and Internet Economics (WINE) 2012: 142–155
     

2011 [ nach oben ]

  • On Dynamics in Basic Netw... - Download
    Lenzner, Pascal On Dynamics in Basic Network Creation GamesSymposium on Algorithmic Game Theory (SAGT) 2011: 254–265
     
  • Balanced Interval Colorin... - Download
    Antoniadis, Antonios; Hüffner, Falk; Lenzner, Pascal; Moldenhauer, Carsten; Souza, Alexander Balanced Interval ColoringSymposium on Theoretical Aspects of Computer Science (STACS) 2011: 531–542
     

2010 [ nach oben ]

  • On Approximate Nash Equil... - Download
    Albers, Susanne; Lenzner, Pascal On Approximate Nash Equilibria in Network DesignWeb and Internet Economics (WINE) 2010: 14–25
     

Community Service

Program Committee Memberships: SAGT'16, IJCAI'18, IJCAI'19, AAAI'20, IJCAI'20, AAAI'21, IJCAI'21, SAGT'21, AAAI'22, IJCAI'22, WINE'22, IJCAI'23, SAGT'23, WINE'23, AAMAS'24, IJCAI'24, SAGT'24

Scientific Reviewer for various Algorithmic Game Theory (e.g. SAGT, WINE, EC), Algorithms (e.g. SPAA, STACS, ESA, ICALP, MFCS) and Artificial Intelligence (e.g. IJCAI, AAAI) conferences and journals.

Organizer of the 6th Day on Computational Game Theory in Potsdam, Germany

General Co-Chair of WINE 2021 in Potsdam, Germany

Local Co-Organizer of ALGO 2022 in Potsdam, Germany

Co-Organizer of the ADYN Summer School on Algorithm Engineering for Network Problems in Potsdam, Germany

 

Teaching

I'm proud and grateful to have received the 2017 FRITSE teaching award.

Courses:

Teaching (as TA)