**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 involved in teaching the courses Algorithmic Problem Solving (with Ziena Elijazyfer and Timo Kötzing) and (Advanced) Competitive Programming Contest Design (with Philipp Fischbeck and Christopher Weyand). Moreover, I'm co-advising the Algorithm Engineering Bachelor Project with TomTom on "Computing Strategic Routes".
- Our paper
**Convergence and Hardness of Strategic Schelling Segregation**(with Hagen Echzell, Tobias Friedrich, Louise Molitor, Marcus Pappik, Friedrich Schöne, Fabian Sommer and David Stangl) was accepted at WINE'19. The preprint is available on arXiv. - Our paper
**Geometric Network Creation Games**(with Davide Bilò, Tobias Friedrich and Anna Melnichenko) was accepted at SPAA'19. The preprint of the paper is on arXiv. - Our paper
**From Hotelling to Load Balancing: Approximation and the Principle of Minimum Differentiation**(with Matthias Feldotto, Louise Molitor and Alexander Skopalik) was accepted as extended abstract at AAMAS'19. The preprint of the paper is on arXiv. The paper will also be presented at CTW'19 in Enschede. - Together with Tobias Friedrich I organized the 6th Day on Computational Game Theory

2020 [ nach oben ]

- On the Tree Conjecture for the Network Creation Game. Theory of Computing Systems 2020: 422--443

2019 [ nach oben ]

- 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 [ nach oben ]

- 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 [ nach oben ]

- 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 [ nach oben ]

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

2015 [ nach oben ]

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

2014 [ nach oben ]

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

2013 [ nach oben ]

- 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 [ nach oben ]

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

2011 [ nach oben ]

- 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 [ nach oben ]

- 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

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:**

- (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

## 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 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