Powered by OpenAIRE graph
Found an issue? Give us feedback
ZENODOarrow_drop_down
ZENODO
Thesis . 2026
License: CC BY
Data sources: Datacite
ZENODO
Thesis . 2026
License: CC BY
Data sources: Datacite
versions View all 2 versions
addClaim

Analysis of Multi-Agent Reinforcement Learning from a Statistical Physics Perspective

Authors: Goll, David;

Analysis of Multi-Agent Reinforcement Learning from a Statistical Physics Perspective

Abstract

Multi-Agent Reinforcement Learning involves interacting agents whose learning processes are coupled through their shared environment, giving rise to emergent, collective dynamics that are sensitive to initial conditions and parameter variations. This thesis explores how a statistical physics perspective can be applied to illuminate the mechanisms governing collective behaviour, levering in particular the toolset of dynamical systems theory. By constructing deterministic approximation models of stochastic algorithms, this approach has uncovered some of the underlying dynamics. Nonetheless, even in the simple independent Q-learning algorithm with a Boltzmann exploration policy, significant discrepancies arise between the actual dynamics and previous approximation models. It is clarified why these models actually do not approximate the original algorithm but interesting variants, which simplify the learning dynamics. To resolve the inconsistencies, a new approximation model is proposed, which explicitly incorporates agents’ update frequencies and demonstrates good agreement with the stochastic dynamics of the real system. The model’s utility is showcased by applying it to the question of spontaneous cooperation in social dilemmas. In the Prisoner’s Dilemma, it reveals that mutual cooperation is merely a metastable transient phase and not a true equilibrium, making it exploitable. Furthermore, a systematic analysis shows that increasing the discount factor exacerbates a “moving target” problem, preventing convergence to a joint policy by inducing oscillations. The oscillations arise from a supercritical Neimark–Sacker bifurcation, where the unique stable fixed point of the learning dynamics transitions into an unstable focus surrounded by a stable limit cycle. These phenomena are observed not only for independent learning but also in memory-one joint-action Q-learning on the iterated Prisoner’s Dilemma. Overall, these results demonstrate that even in trivial two-agent, two-action games, basic algorithms like Q-learning can exhibit complex and unstable learning dynamics.

  • BIP!
    Impact byBIP!
    selected citations
    These citations are derived from selected sources.
    This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    0
    popularity
    This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
    Average
    influence
    This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    Average
    impulse
    This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
    Average
Powered by OpenAIRE graph
Found an issue? Give us feedback
selected citations
These citations are derived from selected sources.
This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Citations provided by BIP!
popularity
This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
BIP!Popularity provided by BIP!
influence
This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Influence provided by BIP!
impulse
This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
BIP!Impulse provided by BIP!
0
Average
Average
Average
Upload OA version
Are you the author of this publication? Upload your Open Access version to Zenodo!
It’s fast and easy, just two clicks!