**Chair for**** Algorithm Engineering**

Hasso Plattner Institute

Office: A-1.5

Tel.: +49 331 5509-419

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

## Research Interests

My research interests are manifold and lie in the intersection of algorithms, game theory and computational complexity.

I'm especially interested in:

- Algorithmic Game Theory, in particular the impact of selfish behavior in optimization problems
- Modeling and analyzing network creation by selfish agents
- Network Design and algorithmic problems on graphs in general

## News

- In the current winter semester I'm teaching Algorithmic Game Theory (with Ágnes Cseh, Timo Kötzing and Anna Melnichenko) and our puzzle-based learning course Algorithmic Problem Solving (with Ágnes Cseh and Timo Kötzing).
- Our paper
**Fair Tree Connection Games with Topology-Dependent Edge Cost**(with Davide Bilò, Tobias Friedrich, Anna Melnichenko and Louise Molitor) has been accepted at FSTTCS'20. The preprint is on arXiv. - Our paper
**A Strategic Routing Framework and Algorithms for Computing Alternative Paths**has been accepted at ATMOS'20. This paper is the outcome of our Algorithm Engineering Bachelor Project with TomTom on "Computing Strategic Routes". - Our
**DFG project**proposal**on Geometric Selfish Network Creation (GEONET)**was granted! I will lead this project together with Tobias Friedrich. - Our paper
**Topological Influence and Locality in Swap Schelling Games**(with Davide Bilò, Vittorio Bilò and Louise Molitor) has been accepted at MFCS'20. The full version is on arXiv. See here, for the MFCS'20 presentation video. - Our paper
**Flow-Based Network Creation Games**(with Hagen Echzell, Tobias Friedrich and Anna Melnichenko) has been accepted at IJCAI'20. The preprint is on arXiv. - In the last summer semester, I taught Graph Algorithms (with Thomas Bläsius) and (Advanced) Competitive Programming (with Christopher Weyand and Philipp Fischbeck). Besides these courses I co-advised the Algorithm Engineering Bachelor Project with TomTom on "Computing Strategic Routes" and the Master Project on "Selfish Creation of Efficient Geometric Networks".

## Short CV

**Education:**

08/2014: PhD degree (Dr. rer. nat.) in computer science from Humboldt-University Berlin, Germany

07/2009: Diploma degree in computer science (Dipl.-Inf.) from Friedrich-Schiller-University Jena, Germany

09/2007 - 07/2009: Studies in theoretical computer science at ETH Zürich, Switzerland

10/2003 - 08/2007: Studies in computer science at Friedrich-Schiller-University Jena, Germany

### Positions:

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

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

10/2014 - 09/2015: Researcher in the Complexity and the Theoretical Computer Science I groups at Friedrich-Schiller-University Jena, Germany

08/2014 - 09/2014: Researcher in the Algorithms & Complexity Group at Humboldt-University Berlin, Germany

10/2009 -07/2014: PhD Student and Researcher in the Algorithms & Complexity Group at Humboldt-University Berlin, Germany

2020 [ to top ]

- On the Tree Conjecture for the Network Creation Game. Theory of Computing Systems 2020: 422--443
- A Strategic Routing Framework and Algorithms for Computing Alternative Paths. Algorithmic Approaches for Transportation Modelling, Optimization, and Systems (ATMOS) 2020: 10:1--10:14
- Fair Tree Connection Games with Topology-Dependent Edge Cost. Foundations of Software Technology and Theoretical Computer Science (FSTTCS) 2020
- Flow-Based Network Creation Games. International Joint Conference on Artificial Intelligence (IJCAI) 2020: 139-145
- Topological Influence and Locality in Swap Schelling Games. International Symposium on Mathematical Foundations of Computer Science (MFCS) 2020: 15:1--15:15

2019 [ to top ]

- From Hotelling to Load Balancing: Approximation and the Principle of Minimum Differentiation. Autonomous Agents and Multiagent Systems (AAMAS) 2019: 1949-1951
- Geometric Network Creation Games. Symposium on Parallelism in Algorithms and Architectures (SPAA) 2019: 323-332
- Convergence and Hardness of Strategic Schelling Segregation. Web and Internet Economics (WINE) 2019: 156-170

2018 [ to top ]

- Schelling Segregation with Strategic Agents. Symposium on Algorithmic Game Theory (SAGT) 2018
- On the Tree Conjecture for the Network Creation Game. Symposium on the Theoretical Aspects of Computer Science (STACS) 2018: 14:1-14:15

2017 [ to top ]

- Selfish Network Creation with Non-Uniform Edge Cost. Symposium on Algorithmic Game Theory (SAGT) 2017: 160-172
- Efficient Best Response Computation for Strategic Network Formation under Attack. Symposium on Algorithmic Game Theory (SAGT) 2017: 199-211
- Brief Announcement: Efficient Best Response Computation for Strategic Network Formation under Attack. Symposium on Parallelism in Algorithms and Architectures (SPAA) 2017: 321-323

2016 [ to top ]

- On Selfish Creation of Robust Networks. Symposium on Algorithmic Game Theory (SAGT) 2016: 141-152

2015 [ to top ]

- Network Creation Games: Think Global - Act Local. Mathematical Foundations of Computer Science (MFCS) 2015: 248-260

2014 [ to top ]

- On selfish network creation. Doctoral Dissertation, Humboldt University of Berlin 2014

2013 [ to top ]

- On Approximate Nash Equilibria in Network Design. Internet Mathematics 2013: 384-405
- On dynamics in selfish network creation. Symposium on Parallelism in Algorithms and Architectures (SPAA) 2013: 83-92

2012 [ to top ]

- Greedy Selfish Network Creation. Web and Internet Economics (WINE) 2012: 142-155

2011 [ to top ]

- On Dynamics in Basic Network Creation Games. Symposium on Algorithmic Game Theory (SAGT) 2011: 254-265
- Balanced Interval Coloring. Symposium on Theoretical Aspects of Computer Science (STACS) 2011: 531-542

2010 [ to top ]

- On Approximate Nash Equilibria in Network Design. Web 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

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

Organizer of the 6th Day on Computational Game Theory

## Teaching

I'm proud and grateful to have received the 2017 FRITSE teaching award together with Thomas Bläsius and Timo Kötzing.

**Courses:**

- Algorithmic Game Theory, Master-Course, Winter 20/21, HPI Potsdam
- Algorithmic Problem Solving, Bachelor-Course, Winter 20/21, HPI Potsdam
- Master Project "Selfish Creation of Efficent Geometric Networks", Summer 2020, HPI Potsdam
- Graph Algorithms, Master-Course, Summer 2020, HPI Potsdam
- (Advanced) Competitive Programming, Bachelor/Master-Course, Summer 2020, HPI Potsdam
- Bachelor Project "Computing Strategic Routes", Winter 19/20, HPI Potsdam
- Algorithmic Problem Solving, Bachelor-Course, Winter 19/20, HPI Potsdam
- (Advanced) Competitive Programming, Bachelor/Master-Course, Summer 2019, HPI Potsdam
- Graph Algorithms, Master-Course, Summer 2019, HPI Potsdam
- Algorithmix, Master-Course, Winter 18/19, HPI Potsdam
- Algorithmic Problem Solving, Bachelor-Course, Winter 18/19, HPI Potsdam
- Seminar on Modern Algorithm Theory, Master-Course, Winter 18/19, HPI Potsdam
- Master Project "Exploring Game-theoretic Schelling Segregation", Winter 18/19, HPI Potsdam
- Introduction to the Mathematics of Algorithms, openHPI MOOC, Summer 2018, HPI Potsdam
- (Advanced) Competitive Programming, Bachelor/Master-Course, Summer 2018, HPI Potsdam
- Graph Algorithms, Master-Course, Summer 2018, HPI Potsdam
- Seminar on Network Science, Master-Course, Summer 2018, HPI Potsdam
- Algorithmix, Master-Course, Winter 17/18, HPI Potsdam
- (Advanced) Algorithmic Problem Solving, Bachelor/Master-Course, Winter 17/18, HPI Potsdam
- Introduction to the Mathematics of Algorithms, openHPI MOOC, Summer 2017, HPI Potsdam
- Seminar on Algorithmic Game Theory, Master-Course, Summer 2017, HPI Potsdam
- (Advanced) Competitive Progamming, Bachelor/Master-Course, Summer 2017, HPI Potsdam
- Graph Algorithms, Master-Course, Summer 2017, HPI Potsdam
- Algorithmix, Master-Course, Winter 16/17, HPI Potsdam
- (Advanced) Algorithmic Problem Solving, Bachelor/Master-Course, Winter 16/17, HPI Potsdam
- Master Project "Strategic Network Formation under Attack", Summer 2016, HPI Potsdam
- (Advanced) Competitive Programming, Bachelor/Master-Course, Summer 2016, HPI Potsdam
- Graph Algorithms, Master-Course, Summer 2016, HPI Potsdam
- Introduction to Algorithms, Bachelor-Course, Winter 2015/16, HPI Potsdam
- Algorithmic Foundations, Bachelor-Course, Summer 2015, FSUJena
- Discrete Modeling, Bachelor-Course, Winter 2014/15, FSUJena

### Teaching (as TA)

*Algorithms & Data Structures*, Summer 2014, HU Berlin*Introduction to Theoretical Computer Science*, Winter 2013/14, HU Berlin*Algorithms & Data Structures*, Summer 2013, HU Berlin*Introduction to Theoretical Computer Science*, Winter 2012/13, HU Berlin*Algorithms & Data Structures*, Summer 2012, HU Berlin*Seminar on Algorithmic Game Theory*, Winter 2011/12, HU Berlin*Algorithms & Data Structures*, Summer 2011, HU Berlin*Seminar on Algorithmic Game Theory*, Winter 2010/11, HU Berlin*Seminar: Perlen der theoretischen Informatik*, Summer 2010, HU Berlin*Seminar on Energy Efficient Algorithms*, Summer 2010, HU Berlin*Introduction to Theoretical Computer Science*, Winter 2009/10, HU Berlin*Theoretical Computer Science*, Winter 2008/09, ETH Zürich*Discrete Mathematics & Logic I*, Winter 2006/07, FSU Jena*Discrete Mathematics & Logic II*, Summer 2006, FSU Jena*Discrete Mathematics & Logic I*, Winter 2005/06, FSU Jena