Hello and welcome to my personal website!

I am a lecturer in machine learning at King’s College London. Before coming to London, I spent four very memorable years as research fellow at Singapore University of Technology & Design hosted by Georgios Piliouras. I earned my PhD in game theory from the mathematics department of Athens University where I was advised by Costis Melolidakis. My interests are in game theory and machine learning, including multi-agent systems, blockchains and artificial intelligence. For my full list of publications please see my [CV] or [google scholar].

Contact details: King’s College London, Department of Informatics, Bush House, Office S5.13. e-mail: stefanos.leonardos@kcl.ac.uk.

For students:

• Funded PhD positions available: If you are interested in doing research in game theory, multi-agent systems, learning in games, reinforcement learning and/or cryptoeconomics (mechanism design/incentives), there are a couple of funded PhD positions available, so please write to me. 
• Office hours (April – September 2023): April onwards, I will be travelling frequently and the regular office hours, Tuesdays 14:00 – 15:30 @ Bush House S5.13, will not be held regularly. To avoid disappointment, please write to me in advance if you intend to come. Sometimes, I am in the lobby area @ S5.01 between 14:00-14:30.

Selected Publications 

• Spotlight @ NeurIPS-21: Exploration-Exploitation in Multi-Agent Competition: Convergence with Bounded Rationality, G. Piliouras and K. Spendlove.
• Best paper award @ AAAI-21: Exploration-Exploitation in Multiagent Learning: Catastrophe Theory Meets Game Theory, G. Piliouras.
• Best paper award @ IEEE-TEM-20: PREStO: A Systematic Framework for Blockchain Consensus Protocols, D. Reijsbergen, G. Piliouras.
• Best paper award @ Decentralized-20: Do Cryptocurrency Prices Camouflage Latent Economic Effects?, C. Koki, G. Piliouras.
• Best paper award @ IEEE-ICBC-19: Weighted Voting on Blockchains: Improving Consensus in Proof of Stake Protocols, D. Reijsbergen, G. Piliouras. 
• Best paper award @ MARBLE-19: Oceanic Games: Centralization Risks and Incentives in Blockchain Mining, N. Leonardos, G. Piliouras. 

Ethereum Collaboration

• @ FC-23, Optimality Despity Chaos in Fee Markets, D. Reijsbergen, B. Monnot & G. Piliouras. 
• @ IEEE-Blockchain-21, Transaction Fees on a Honeymoon: Ethereum’s EIP-1559 One Month Later, D. Reijsbergen, B. Monnot, et. al.
• @ AFT-21, Dynamical Analysis of the EIP-1559 Ethereum Fee Market, S. Leonardos, B. Monnot, D. Reijsbergen, S. Skoulakis & G. Piliouras.
• @ WINE-20, Ethereum’s Transaction Fee Reform in EIP 1559, B. Monnot, Q. Z. Hum, C.S. M. Koh, S. Leonardos & G. Piliouras.
• @ IEEE-ICBC-19, Incentives in Ethereum’s Hybrid Casper Protocol,V. Buterin, D. Reijsbergen, S. Leonardos & G. Piliouras.

News

• @ NUS, Institute for Mathematical Studies: Excited to be invited by Panayotis Mertikopoulos to give a talk @ the Games, Learning, and Networks Workshop, 17-21 April 2023 (in person).   
• @ ACM TEAC: a new paper on catastrophe mechanism design in population games.
• @ University of Leeds: Excited to be invited by Evangelos Pournaras to give a talk @ the School of Computing Colloquium series, on February 7 at 12pm, 2023 (in person).
• @ University of Oxford: Excited to be invited by Andreas Galanis to give a talk at the Algorithm and Complexity Theory seminar series, on February 2 at 2pm, 2023 @ the Department of Computer Science (in person).
• @ FC 2023: a new paper on optimality and chaos in transaction fee markets.
• @ IJCAI 2023: I am delighted to join the program committee.
• @ AAMAS 2023: I am delighted to join the program committee.
• @ WINE 2022: I am delighted to join the program committee.
• @ IJTCS 2022: Excited to give an invited talk at the Game Theory and Blockchain track, August 15-19, 2022, @ City University of Hong Kong (virtual).
• @ MARBLE 2022: The technical program is now online! Exciting upcoming 100% physical event with tutorials, keynotes and fantastic activities!
• @ ETHconomics – Devconnect April 21st, Amsterdam: I am excited to give a talk on the EIP-1559 transaction fee mechanism.
• I will be giving an invited talk at the University of Edinburgh, School of Informatics on April 6.
• Invited upcoming talks @ University of Southampton and @ King’s College London. Details coming soon.
• @ AAMAS 2022: I am honored to join the PC of the Learning with Strategic Agents Workshop (LSA 2022). 
• Invited upcoming talks @ Royal Holloway University of London @ Tilburg University, @ Heriot-Watt University and @ Edindurgh Napier University.
• Upcoming talk @ NKUA on April 1st (no lies :)): I will talk about our two papers [here] and [here] on Exploration-Exploitation in Multi-Agent Learning in the Statistics and Operations Research Seminar @ NKUA.
• Upcoming talk @ SUTD on February 25th (virtual): I will present our recent works [here] and [here] (e-mail me for the link).
• @ ACM DLT: I will be one of the guest editors in the special issue on Mathematical Research for Blockchain Economy! See the call for papers. 
• @ ICLR 2022: Global Convergence of Multi-Agent Policy Gradient in Markov Potential Games
• @ Artificial Intelligence journal: the invited extended version of our AAAI article (see also this featured video) is forthcoming!
• @ SAGT 2022: I am delighted to join as a PC member.
• YouTube video of our AAAI talk by the State-of-the-Art AI Research channel.
• @ MARBLE 2022: I am delighted to be TCP co-chair together with Elise Alfieri.
• @ ICDCS 2022: I am delighted to join as a PC member.
• @ IEEE Blockchain-2021: a new paper on Ethereum’s EIP-1559.
• @ Research in International Business and Finance: Predictability of Cryptocurrencies via Bayesian Hidden Markov Models, C. Koki, G. Piliouras.
• Talk @ ACM AFT-21: on our new paper about Ethereum’s EIP-1559.
• @ ICML Workshop on RL: poster on the Convergence of Policy Gradient in Markov Potential Games, W. Overman, I. Panageas, G. Piliouras.
• @ arXiv: From Griefing to Stability in Blockchain Mining Economies, Y.K. Cheung, S. Sridhar, G. Piliouras.
• @ FOCODILE: contributed talk on our paper on EIP 1559 on June 18, 2021.
• @ Economics Letters: Partial Passive Ownership Holdings, Licensing and Taxation, E. Petrakis, P. Skartados, G. Stamatopoulos.
• Talk @ IJCAI-21: Learning in Markets, Y.K. Cheung, G. Piliouras.
• @ Athens University of Economics and Business: talk on game theory and blockchains invited by E. Markakis on April 15, 2021.
• Media coverage for our @ AAAI paper:  [1,2,3,4].
• Talk @ AAAI-21: on February 4, 2021, I will be presenting our [paper] on exploration – exploitation in multi-agent learning.
• @ Annals of Operations Research: Monopoly Pricing in Vertical Markets with Demand Uncertainty, C. Melolidakis, C. Koki.
• @ AtheCrypt2021: I am delighted to be invited to give talk on our [paper] on EIP 1559 on January 16, 2021.
• @ European Journal of Operations Research: Strategic Customer Behavior, Y. Dimitrakopoulos, A. Economou.
• @ WINE-20: contributed talks on our working papers at the Workshop on Blockchain and Game Theory.
• Media coverage for our @ IEEE-ICBC paper: [1].
• @ Ethereum: check out our new [paper] on Incentives in Ethereum’s Hybrid Casper Protocol, V. Buterin, D. Reijsbergen, G. Piliouras.
• Media coverage for our @ MARBLE paper: [1,2].