News
A New Beginning 1 June 2024
After more than 7 very successful years at Goethe University, our group will be moving to RWTH Aachen University over the summer. We are excited about the new opportunities and thank everyone for the great time in Frankfurt.
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New Paper in Journal of Artificial Intelligence Research 5 May 2024
Computational aspects of fair division have recently received a lot of attention in algorithms and social choice. Especially fair allocation of indivisible items (like real-estate, cars, jewelry, etc.) to multiple agents is a very challenging problem. In our new paper ''Best of Both Worlds: Agents with Entitlements'' (by Martin Hoefer, Marco Schmalhofer, Giovanna Varricchio) we propose randomized algorithms with ex-ante and ex-post fairness guarantees when agents can have heterogeneous entitlements or priorities. Our guarantees refer to variants of envy-freeness (where agents do not (strongly) prefer bundles of other agents) and are optimal for additive valuations. We also propose the first (ex-ante + ex-post)-guarantees beyond additive valuations. The paper has been accepted for publication in the Journal of Artificial Intelligence Research, a top journal in artificial intelligence.
New Paper in Distributed Comptuting 28 Mar 2024
Opinion formation is usually modeled as a process where agents adjust their publicly expressed views to popularity and similarity in their peer group. In the classic Hegselmann-Krause model, opinions are expressed by numerical values, and agents adapt to opinions within a bounded range around their current value. While convergence properties in this model are reasonably well-understood with synchronous updates of the entire population, our new paper ''Asynchronous Opinion Dynamics in Social Networks'' (by Petra Berenbrink, Martin Hoefer, Pascal Lenzner, Malin Rau, Dominik Schallmoser, Daniel Schmand) reveals that even asynchronous updates do not require substantially more time. Moreover, we provide parametrized bounds on the convergence time to near-stable states when the interactions between agents are apriori restricted to a social network. The paper has been accepted for publication in Distributed Computing, a top journal in the area.
New Paper at STACS 2024 13 Dec 2023
Our paper ''Algorithms for Claims Trading'' (by Martin Hoefer, Carmine Ventre, Lisa Wilhelmi) was accepted at the 41st Symposium on Theoretical Aspects of Computer Science (STACS 2024), a leading conference in theoretical computer science.
New Paper in Mathematics of Operations Research 11 Dec 2023
In our paper ''Flow Allocation Games'' (by Nils Bertschinger, Martin Hoefer, Daniel Schmand) we study a game-theoretic model for clearing in financial networks. Network clearing requires that banks determine if they have enough assets to clear their debt -- and if not, which debt contract is cleared to which extent. Naturally, each bank has an incentive to maximize the debt that is cleared. This represents a natural network circulation problem, in which a node allocates flow to outgoing capacitated edges in order to maximize the amount of flow circulating through the node. We study a game-theoretic version of this problem and characterize the existence and computational complexity of equilibria. Our results reveal an interesting dichotomy: If allocation strategies are monotone and ordering-based over individual flow units, then for a variety of social objective functions, there exist optimal equilibria which can also be computed in polynomial time. If allocation strategies are ordering-based over entire edges, equilibria can be absent or very hard to compute. The paper has been accepted for publication in Mathematics of Operations Research, a leading journal in operations research.
New Paper at AAAI 2024 9 Dec 2023
Our paper ''Information Design for Congestion Games with Unknown Demand'' (by Svenja Griesbach, Martin Hoefer, Max Klimm, Tim Koglin) was accepted at the 38th Conference on Artificial Intelligence (AAAI 2024), one of the two international top conferences in artificial intelligence.
New Paper in Journal of Artificial Intelligence Research 24 Nov 2023
New
algorithms to compute market equilibria in the standard
Fisher market model are discussed in our new paper ''Competitive
Equilibria with a Constant Number of Chores'' (by Jugal
Garg, Martin Hoefer, Peter McGlaughlin, Marco
Schmalhofer).
When agents have piecewise linear utility functions for goods, computing an equilibrium is known to be a hard problem. Interestingly, the addition of a small number of
New Paper at NeurIPS 2023 23 Sep 2023
Our paper ''ε-Fractional Core Stability in Hedonic Games'' (by Simone Fioravanti, Michele Flammini, Bojana Kodric, Giovanna Varricchio) was accepted at the 37th Conference on Neural Information Processing Systems (NeurIPS 2023), the international top-conference in machine learning.
Giovanna Varricchio moves to Università della Calabria 15 Sep 2023
Our group member Giovanna Varricchio accepted an offer to become junior assistant professor (RTD-A) at Università della Calabria. Congratulations!
New Paper in SIAM Journal on Discrete Mathematics 4 Sep 2023
The focus of our paper ''Stochastic Probing with Increasing Precision'' (by Martin Hoefer, Kevin Schewior, Daniel Schmand) are algorithms for probing problems, in which we have a number of choice options (e.g., job candidates, investments, vaccination strategies, etc.). Each option has an unknown quality drawn from a known independent distribution. Before we select an option, we can learn about their quality by testing options adaptively. A test shows whether or not the value is above or below the median value of the conditional distribution (based on outcomes of previous tests). We propose and analyze testing algorithms that provide provably near-optimal performance. The paper has been accepted for publication in SIAM Journal of Discrete Mathematics.
Welcome 1 Sep 2023
Our former secretary Marta Soares moved to a new position in HRZ of Goethe University. We thank her for the excellent service, and we wish her all the best!
At the same time, we welcome Teresa Fischer as the new secretary in our group.
Welcome 1 Sep 2023
We welcome Lars Huth as a new member of our group.
Welcome 1 Aug 2023
We welcome Tolga Tel as a new member of our group.
DFG Research Unit 27 Jun 2023
The German Research Foundation prolongs the financial support for our research unit Algorithms, Dynamics, and Information Flow in Networks (ADYN) until 2026. This will allow us to conduct exciting new research on the understanding of dynamic processes on networks and their relation to efficient algorithms, e.g., in the analysis of spreading processes, distributed network algorithms, network generation models, in the context of static as well as dynamic and temporal networks.
New Paper at ESA 2023 23 Jun 2023
Our paper ''Threshold Testing and Semi-Online Prophet Inequalities'' (by Martin Hoefer, Kevin Schewior) was accepted at the 31st European Symposium on Algorithms (ESA 2023), the European top-conference in design and analysis of algorithms.
Graduation Award 22 Jun 2023
Our former student Henri Froese received the award for best B.Sc. graduate of 2022/23 in Computer Science at Goethe University. Congratulations, well deserved!
New Paper in Mathematics of Operations Research 1 Jun 2023
In our paper ''Satiation in Fisher Markets and Approximation of Nash Social Welfare'' (by Jugal Garg, Martin Hoefer, Kurt Mehlhorn) we analyze the existence and structure of equilibria in an extension of the classic Fisher market with divisible goods. We consider the impact of satiation in the utility of the agents, i.e., utility caps for the allocation among buyers, and/or earning caps for incomes of sellers. We characterize the existence and complexity of equilibria for capped linear utilities. Moreover, we provide an algorithm to round approximate equilibria in markets with indivisible goods. The algorithm comes with a provable approximation guarantee for the Nash social welfare. The paper has been accepted for publication in Mathematics of Operations Research, a leading journal in operations research.
Night of Science 26 May 2023
Join us on June 16/17 for the next edition of Night of Science at Riedberg Campus of GU.
Our talk will be at 2:00am in OSZ H5. Looking forward to seeing you there!
F.A.Z. Digitec Podcast 13 May 2023
The most recent edition of the digitec podcast (in German) of Frankfurter Allgemeine Zeitung features an interview with Martin Hoefer and Sebastian Faust on the impact of blockchain, algorithms, and AI.
Two Papers at IJCAI 2023 19 Apr 2023
Two papers of our group were accepted as full papers at the 32nd International Joint Conference on Artificial Intelligence (IJCAI 2023), one of the two international top conferences in artificial intelligence:
- Delegated Online Search
(by Pirmin Braun, Niklas Hahn, Martin Hoefer, Conrad Schecker) - Existence and Computation of Epistemic EFX Allocations
(by Ioannis Caragiannis, Jugal Garg, Nidhi Rathi, Eklavya Sharma, Giovanna Varricchio)
DFG Grant 31 Jan 2023
In a new three-year project Online Algorithms for Bayesian Persuasion funded by the German Research Foundation, we study algorithmic problems for signaling and persuasion. These problems arise among agents with asymmetric information in the context of many economic applications, e.g., product recommendations, consulting, and more. An algorithmic challenge we tackle in the project are online scenarios, in which information is revealed sequentially to the informed agent(s). The project is a cooperation with Rann Smorodinsky from the Technion.
Two Papers at AAMAS 2023 4 Jan 2023
Two papers of our group were accepted as full papers at the 22nd International Conference on Autonomous Agents and Multiagent Systems (AAMAS 2023), the international top conference on multiagent systems:
- Equilibria and Convergence in Fire-Sale Games
(by Nils Bertschinger, Martin Hoefer, Simon Krogmann, Pascal Lenzner, Steffen Schuldenzucker, Lisa Wilhelmi) - Best of Both Worlds: Agents with Entitlements
(by Martin Hoefer, Giovanna Varricchio, Marco Schmalhofer)
ATHENE Grant on Decentralized Exchanges 29 Nov 2022
In a new four-year project Cryptography and Game Theory for Decentralized Exchanges funded within the ATHENE Center for Applied Cybersecurity, we study algorithmic and economic aspects of decentralized exchanges (DEXes). An intriguing innovation of DEXes is the automated market maker (AMM), a smart contract running on a blockchain that manages a pool of assets and executes trades using a carefully designed exchange mechanism. Our main goal is to understand and improve the algorithmic, economic, and security aspects of this technology. The project is a joint effort with Sebastian Faust from TU Darmstadt.
New Paper at AAAI 2023 20 Nov 2022
Our paper ''PAC Learning and Stabilizing Hedonic Games: Towards a Unifying Approach'' (by Simone Fioravanti, Michele Flammini, Bojana Kodric, Giovanna Varricchio) was accepted at the 37th AAAI Conference on Artificial Intelligence (AAAI 2023), one of the two international top conferences in artificial intelligence.
Dagstuhl Seminar 11 Nov 2022
Thanks to all the participants who made our Dagstuhl seminar on Computational Social Dynamics such an enjoyable and extremely productive event.
Invited Talk 29 Jul 2022
Martin Hoefer will give an invited talk at the 12th Days on Computational Game Theory on Sep 29/30, 2022 at University of Bremen.
Welcome 1 Jul 2022
Our former secretary Jutta Nadland retired on June 30. We thank her for the many contributions to our team and the excellent service, and we wish her all the best!
At the same time, we welcome Marta Soares as the new secretary in our group.
New Paper at SAGT 2022 1 July 2022
Our paper ''Seniorities and Minimal Clearing in Financial Network Games'' (by Martin Hoefer, Lisa Wilhelmi) was accepted at the 15th Int. Symposium on Algorithmic Game Theory (SAGT 2022).
Graduation Awards 30 Jun 2022
Several (former) members of our group received awards for oustanding performances among the 2021/22 graduates in Computer Science at Goethe University:
- Niklas Hahn received the Rainer Kemp dissertation award for his Ph.D. thesis.
- Conrad Schecker and Elias Pitschmann received awards for the best M.Sc. graduates.
Congratulations to all of them, well deserved!
New Paper at EC 2022 9 May 2022
Our paper ''Public Signals in Network Congestion Games'' (by Svenja Griesbach, Martin Hoefer, Max Klimm, Tim Koglin) was accepted at the 23rd ACM Conference on Economics and Computation (EC 2022), the international top conference at the intersection of computer science and economics.
Thesis Defense 27 Apr 2022
Niklas Hahn successfully defended his thesis entitled Algorithms for Bayesian Persuasion and Delegated Search. Starting in May 2022 he will be a postdoc in the RO team of the LIP6 lab at Sorbonne University.
Congratulations to Dr. Hahn!
New Paper at IJCAI 2022 20 Apr 2022
Our paper ''Approximate Strategyproof Mechanisms for the Additively Separable Group Activity Selection Problem'' (by Michele Flammini, Giovanna Varricchio) was accepted at the 31st Int. Joint Conference on Artificial Intelligence (IJCAI 2022), one of the two international top conferences in artificial intelligence.
Visitor 5 Apr 2022
Kevin Schewior is visiting our group Apr 19-21.
Welcome 1 Apr 2022
We welcome Conrad Schecker as a new member of our group.
New Paper in Games and Economic Behavior 18 Jan 2022
In our paper ''The Secretary Recommendation Problem'' (by Niklas Hahn, Martin Hoefer, Rann Smorodinsky) we study a basic sequential recommendation problem. A sender (e.g., a social network) decides to recommend taking an action (e.g., clicking on certain media content) to a receiver (user in the network). Actions can have different utilities for sender and receiver, which are known upfront to the sender (but not to the receiver). As such, the receiver must rely on the sender to give informative advice. We analyze the scenario when actions become (un-)available sequentially over time. Our results are near-optimal algorithms to compute good recommendation strategies for the sender. On a technical level, we provide a novel connection between classic stopping theory and persuasion/signaling aspects. The paper has been accepted for publication in Games and Economic Behavior, the top journal in game theory.
New Paper at AAMAS 2022 19 Dec 2021
Our paper ''Asynchronous Opinion Dynamics in Social Networks'' (by Petra Berenbrink, Martin Hoefer, Dominik Kaaser, Pascal Lenzner, Malin Rau, Daniel Schmand) was accepted as full paper at the 21st International Conference on Autonomous Agents and Multiagent Systems (AAMAS 2022), the international top conference on multiagent systems.
New Paper at AAAI 2022 01 Dec 2021
Our paper ''Maximizing Nash Social Welfare in 2-Value Instances'' (by Hannaneh Akrami, Bhaskar Ray Chaudhury, Martin Hoefer, Kurt Mehlhorn, Marco Schmalhofer, Golnoosh Shahkarami, Giovanna Varricchio, Quentin Vermande, Ernest van Wijland) was accepted at the 36th AAAI Conference on Artificial Intelligence (AAAI 2022), one of the two international top conferences in artificial intelligence.
New Paper in Journal of Artificial Intelligence Research 26 Nov 2021
In ''Fair Division of Indivisible Goods for a Class of Concave Valuations'' (by Bhaskar Ray Chaudhury, Yun Kuen Cheung, Jugal Garg, Naveen Garg, Martin Hoefer, Kurt Mehlhorn) we study approximation algorithms for fair allocation of a set of indivisible goods to a set of agents. Our algorithm computes a near-optimal allocation in terms of the geometric mean (also termed Nash social welfare) of agent valuations. In addition, the allocation satisfies approximate versions of envy-freeness, a standard fairness concept in the literature. Our results unify and extend existing techniques for approximating Nash social welfare for additive valuations to a more general, concave and non-separable class of valuation functions. The paper has been accepted for publication in Journal of Artificial Intelligence Research, a top journal in artificial intelligence.
Graduation Award 22 Oct 2021
Lisa Wilhelmi received the award for the best M.Sc. graduate of 2020/21 in Computer Science at Goethe University. Congratulations, well deserved!
New Paper in Mathematics of Operations Research 8 Sep 2021
In our paper ''Algorithms for Persuasion with Limited Communication'' (by Ronen Gradwohl, Niklas Hahn, Martin Hoefer, Rann Smorodinsky) we study the problem faced by a recommendation engine (e.g., a website for hotel booking or travel) that wants to persuade a user with a recommendation. We analyze restrictions on the signal space such that there are more potential actions by the user than signals that can be issued for recommendation. For symmetric instances, when a priori all actions have similar profits, we characterize and design efficient algorithms for optimal recommendation schemes for the engine. In a subclass of instances, where profits are independent among actions, we obtain an algorithm that computes a near-optimal scheme. The paper has been accepted for publication in Mathematics of Operations Research, a leading journal in operations research.
Tutorial on Algorithms and Information Design at SAGT 2021 27 Aug 2021
Stay tuned for our tutorial on Algorithmic Challenges in Information Design; on 21 Sep 2021 at SAGT in Aarhus (and online).
New Paper at SAGT 2021 29 Jun 2021
Our paper ''When Dividing Mixed Manna is Easier than Dividing Goods: Competitive Equilibria with a Constant Number of Chores'' (by Jugal Garg, Martin Hoefer, Peter McGlaughlin, Marco Schmalhofer) was accepted at the 14th Int. Symposium on Algorithmic Game Theory (SAGT 2021).
New Paper at IJCAI 2021 29 Apr 2021
Our paper ''Stochastic Probing with Increasing Precision'' (by Martin Hoefer, Kevin Schewior, Daniel Schmand) was accepted at the 30th Int. Joint Conference on Artificial Intelligence (IJCAI 2021), one of the two international top conferences in artificial intelligence.
New Paper in American Economic Journal: Microeconomics 17 Mar 2021
In our paper ''Reaping the Informational Surplus in Bayesian Persuasion'' (by Ronen Gradwohl, Niklas Hahn, Martin Hoefer, Rann Smorodinsky) we study a competitive scenario, in which several experts with knowledge about the state of the world want to influence the choice of a decision maker (e.g., consultants/lobbyists try to influence policy decisions of the government). Even if there is only slight uncertainty for each expert about the interests of other experts, then the decision maker can extract the full informational surplus -- by restricting to listen only to one expert, the emerging competition motivates them to reveal all information about the state of the world. The paper has been accepted for publication in American Economic Journal: Microeconomics, a top journal in economics.
Daniel Schmand moves to University of Bremen 05 Feb 2021
Our group member Daniel Schmand accepted an offer to become assistant professor in discrete optimization at University of Bremen. Congratulations Prof. Schmand!
Welcome 1 Feb 2021
We welcome Tim Koglin as a new member of our group.
WINE 2020 Live Stream 26 Nov 2020
The 16th Conf. Web and Internet Economics (WINE 2020), one of the main events in economics and computation, is happening virtually Dec 7-11, 2020. There will be a free live stream on YouTube with all invited and contributed talks. All talks are scheduled within a (Europe-friendly) time window from 8am to 5pm CET.
New Paper at ITCS 2021 2 Nov 2020
Our paper ''Algorithmic Persuasion with Evidence'' (by Martin Hoefer, Pasin Manurangsi, Alexandros Psomas) was accepted at the 12th Int. Conf. Innovations in Theoretical Computer Science (ITCS 2021), a top conference in theory of computing.
Welcome 1 Nov 2020
We welcome Giovanna Varricchio as a new member of our group.
Welcome 1 Oct 2020
We welcome Lisa Wilhelmi as a new member of our group.
New Paper at SODA 2021 30 Sep 2020
Our paper ''Algorithms for Persuasion with Limited Communication'' (by Ronen Gradwohl, Niklas Hahn, Martin Hoefer, Rann Smorodinsky) was accepted at the 31st Symposium on Discrete Algorithms (SODA 2021), the international top conference in design and analysis of algorithms.
New Paper in Networks 29 Sep 2020
In our paper ''Packing Returning Secretaries'' (by Martin Hoefer, Lisa Wilhelmi) we analyze extensions of the classic secretary problem and relax the assumption that the decision for a specific element must be made instantaneously. Our results are approximation guarantees for a wide class of combinatorial packing problems, such as knapsack, matching or independent set. Moreover, we are interested in scenarios where the decision for an element can be postponed, with the goal of selecting an optimal set of elements with the minimum number of postponements. The paper has been accepted for publication in Networks.
New Paper at COLT 2020 26 May 2020
In the new paper ''A Nearly Optimal Variant of the Perceptron Algorithm for the Uniform Distribution on the Unit Sphere'', Marco Schmalhofer shows that a simple variant of the classic perceptron algorithm provides near-optimal guarantees for PAC-learning of halfspaces, where examples are drawn uniformly at random on the hypersphere. The paper was accepted at the 33rd Annual Conference on Learning Theory (COLT 2020), the international top conference in learning theory.
Two Papers at EC 2020 6 May 2020
Two papers from our group were accepted at the 21st ACM Conference on Economics and Computation (EC 2020), the international top conference at the intersection of computer science and economics:
- The Secretary Recommendation Problem
(by Niklas Hahn, Martin Hoefer, Rann Smorodinsky) - Portfolio Compression in Financial Networks: Incentives and Systemic Risk
(by Steffen Schuldenzucker, Sven Seuken)
DFG Research Group 29 Apr 2020
The German Research Foundation grants funding for a new research group on Algorithms, Dynamics, and Information Flow in Networks. The group is headed by Martin Hoefer, the participating PIs are Petra Berenbrink (Hamburg), Nils Bertschinger, Amin Coja Oghlan, Ulrich Meyer (Frankfurt) and Tobias Friedrich (HPI/Potsdam). The goals are to advance our understanding of dynamic processes on networks and their relation to efficient algorithms, e.g., in the analysis of spreading processes, distributed network algorithms, network generation models, as well as application domains such as financial markets.
New Paper at IJCAI 2020 21 Apr 2020
Our paper ''Prophet Inequalities for Bayesian Persuasion'' (by Niklas Hahn, Martin Hoefer, Rann Smorodinsky) was accepted at the 29th Int. Joint Conference on Artificial Intelligence (IJCAI 2020), one of the two international top conferences in artificial intelligence.
Visitor 1 Mar 2020
Kevin Schewior is visiting our group Mar 9-13.
DFG Grant 14 Feb 2020
In a our new three-year project Algorithms for Fair Allocation of Indivisible Goods funded by the German Research Foundation, we study algorithmic problems for fair assignment of indivisble goods, which arise, e.g., when assigning students to schools, splitting an inheritance, sharing rooms in an appartment, etc. Jugal Garg from the University of Illinois at Urbana-Champaign collaborates with us as a Mercator Fellow.
Welcome 16 Jan 2020
We welcome Marco Schmalhofer as a new member of our group.
New Paper in Mathematics of Operations Research 14 Dec 2019
In our paper ''Efficient Black-Box Reductions for Separable Cost Sharing'' (by Tobias Harks, Martin Hoefer, Anja Schedel, Manuel Surek) we study cost sharing protocols for resource allocation with selfish agents. In scenarios related to facility location and Steiner network design we show how approximation algorithms for optimization can be used in a black-box fashion to construct protocols with good stable states. The paper has been accepted for publication in Mathematics of Operations Research, a leading journal in operations research.
Visitor 3 Dec 2019
Rann Smorodinsky is visiting our group Dec 17-20.
Visitor 15 Nov 2019
Kevin Schewior is visiting our group Nov 21/22.
Visitor 1 Nov 2019
Andreas Abels is visiting our group Nov 12-14.
New Paper at ITCS 2020 31 Oct 2019
Our paper ''Strategic Payments in Financial Networks'' (by Nils Bertschinger, Martin Hoefer, Daniel Schmand) was accepted at the 11th Int. Conf. Innovations in Theoretical Computer Science (ITCS 2020), a top conference in theory of computing.
Welcome 1 Sep 2019
We welcome Steffen Schuldenzucker as a new member of our group.
New Paper at SAGT 2019 1 Jul 2019
Our paper ''The Online Best Reply Algorithm for Resource Allocation Problems'' (by Max Klimm, Daniel Schmand, Andreas Tönnis) was accepted at the 12th Int. Symposium on Algorithmic Game Theory (SAGT 2019).
New Paper in ACM Transactions on Economics and Computation 17 May 2019
In our paper ''Earning and Utility Limits in Fisher Markets'' (by Xiaohui Bei, Jugal Garg, Martin Hoefer, Kurt Mehlhorn) we study a generalization of the classic Fisher market model in which participants have limits for their utility. We provide algorihtms for computing equilibria, which have a number of desirable fairness and efficiency guarantees. The paper has been accepted for publication in ACM Transactions on Economics and Computation.
Visitor 6 May 2019
Thomas Kesselheim is visiting our group May 6-7.
New Paper at ICALP 2019 25 Apr 2019
Our paper ''Network Investment Games with Wardrop Followers'' (by Daniel Schmand, Marc Schröder, Alexander Skopalik) was accepted at the 46th Int. Colloquium on Automata, Languages, and Programming (ICALP 2019), the top conference in theory of computing in Europe.
New Paper in ACM Transactions on Algorithms 9 Mar 2019
In our paper ''Ascending-Price Algorithms for Unknown Markets'' (by Xiaohui Bei, Jugal Garg, Martin Hoefer) we show how simple price adaptation algorithms can rapidly lead an exchange economy to equilibrium, even if many details such as size or structure of the market are unknown in the beginning. The paper has been accepted for publication in ACM Transactions on Algorithms, a top journal in the field of algorithms.
New Paper in Mathematics of Operations Research 20 Feb 2019
Upon retirement of an employee, a common practice in many areas is to hire a new person early with a period of overlap. This strategy can have significant advantages over strictly sequential employment, as shown by Daniel Schmand and his colleagues. The paper ''Hiring Secretaries over Time: The Benefit of Concurrent Employment'' (by Yann Disser, John Fearnley, Martin Gairing, Oliver Göbel, Max Klimm, Daniel Schmand, Alexander Skopalik, Andreas Tönnis) has been accepted for publication in Mathematics of Operations Research, a leading journal in operations research.
Visitor 2 Feb 2019
Rann Smorodinsky is visiting our group Feb 25-28.
Visitor 23 Jan 2019
Warut Suksompong is visiting our group Feb 18/19.
New Paper at AAMAS 2019 23 Jan 2019
Our paper ''Tracing Equilibrium in Dynamic Markets via Distributed Adaptation'' (by Yun Kuen Cheung, Martin Hoefer, Paresh Nakhe) has been accepted as a full paper at the 18th International Conference on Autonomous Agents and Multiagent Systems (AAMAS 2019), the international top conference on multiagent systems.
Artikel in Forschung Frankfurt 4 Dec 2018
Das Wissenschaftsmagazin widmet sich in der aktuellen Ausgabe dem Thema "Mit Unsicherheit rechnen" und unserer Arbeit zu Online-Algorithmen.
New Paper in SAGT'17 Special Issue 2 Oct 2018
As one of the best papers from SAGT 2017, our paper ''Opinion Formation Games with Aggregation and Negative Influence'' (by Markos Epitropou, Dimitris Fotakis, Martin Hoefer, Stratis Skoulakis) has been accepted for publication in the special issue of Theory of Computing Systems.
Welcome 01 Oct 2018
We welcome Daniel Schmand as a new member of our group.
New Paper at FSTTCS 2018 24 Sep 2018
Our paper ''On Fair Division for Indivisible Items'' (by Bhaskar Ray Chaudhuri, Yun Kuen Cheung, Jugal Garg, Naveen Garg, Martin Hoefer, Kurt Mehlhorn) has been accepted at the 38th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2018).
New Paper at ISAAC 2018 31 Aug 2018
Our paper ''Packing Returning Secretaries'' (by Martin Hoefer, Lisa Wilhelmi) has been accepted at the 29th International Symposium on Algorithms and Computation (ISAAC 2018), the top conference in theory of computing in Asia.
Thesis Defense 13 Aug 2018
Paresh Nakhe successfully defended his thesis entitled On Bandit Learning and Pricing in Markets.
Congratulations to Dr. Nakhe!
Thesis Defense 23 Jul 2018
Bojana Kodric successfully defended her thesis entitled Incentives in Dynamic Markets at Saarland University.
Congratulations to Dr. Kodric!
New Paper in Artifical Intelligence 4 Jun 2018
Our paper ''Dynamics in Matching and Coalition Formation Games with Structural Constraints'' (by Martin Hoefer, Daniel Vaz, Lisa Wagner) has been accepted for publication in Artifical Intelligence, the top journal in the field.
Visitor 14 May 2018
Max Klimm is visiting our group May 14-17.
New Paper at ICALP 2018 16 Apr 2018
Our paper ''Efficient Black-Box Reductions for Separable Cost Sharing'' (by Tobias Harks, Martin Hoefer, Anja Huber, Manuel Surek) was accepted at the 45th Int. Colloquium on Automata, Languages, and Programming (ICALP 2018), the top conference in theory of computing in Europe.
Visitor 12 Mar 2018
Rann Smorodinsky is visiting our group March 13-17.
GIF Grant 1 Jan 2018
In a new project funded by the German-Israeli Foundation, we study algorithmic problems with sequential information aggregation, such as recommendation systems and the wisdom of the crowd (e.g., in platforms like TripAdvisor or Booking.com) or sequential matching problems (e.g., in Internet marketing or organ donation). The project runs for three years and is a collaboration with Rann Smorodinsky from the Technion.
Visitors 4 Dec 2017
Tobias Harks is visiting our group December 4-5, and Yun Kuen Cheung is visiting December 5-8.
New Paper at SODA 2018 29 Sep 2017
Our paper ''Approximating the Nash Social Welfare with Budget-Additive Valuations'' (by Jugal, Garg, Martin Hoefer, Kurt Mehlhorn) was accepted at the 29th Symposium on Discrete Algorithms (SODA 2018), the international top conference in design and analysis of algorithms.
New Paper at WINE 2017 26 Sep 2017
In his paper ''Dynamic Pricing in Competitive Markets'', Paresh Nakhe highlights how learning algorithms for revenue maximization can lead markets quickly into equilibrium states. The paper has been accepted at the 13th Conference on Web and Internet Economics (WINE 2017) in Bangalore, India.
Visitor 14 Jul 2017
Xiaohui Bei is visiting our group July 15-30.
Three Papers at SAGT 2017 22 Jun 2017
Three papers of our group were accepted at the 10th Int. Symposium on Algorithmic Game Theory (SAGT 2017):
- Earning Limits in Fisher Markets with Spending-Constraint Utilities
(by Xiaohui Bei, Jugal Garg, Martin Hoefer, Kurt Mehlhorn) - Opinion Formation Games with Aggregation and Negative Influence
(by Markos Epitropou, Dimitris Fotakis, Martin Hoefer, Stratis Skoulakis) - On Proportional Allocation in Hedonic Games
(by Martin Hoefer, Wanchote Jiamjitrak)
New Paper at ICALP 2017 18 Apr 2017
Our paper ''Combinatorial Secretary Problems with Ordinal Information'' (by Martin Hoefer, Bojana Kodric) was accepted at the 44th Int. Colloquium on Automata, Languages, and Programming (ICALP 2017), the top conference in theory of computing in Europe. This year's edition is going to take place in Warsaw, Poland, in July 2017.
Website Launch 28 Mar 2017
Our new website is online.
New Paper at WINE 2016 16 Dec 2016
Our paper ''Smoothness for Simultaneous Composition of Mechanisms with Admission'' (by Martin Hoefer, Bojana Kodric, Thomas Kesselheim) was presented and published at the 12th Conference on Web and Internet Economics (WINE 2016) in Montreal, Canada.
Invited Talk at SAGT 2017 23 Nov 2016
Martin Hoefer will give an invited talk at the 10th Int. Symposium on Algorithmic Game Theory (SAGT 2017) in L'Aquila, Italy, on September 12-14, 2017.