Lucas Affonso


Mathematical statistical mechanics
Portrait of Lucas Affonso

I am a postdoctoral researcher at the Institute of Mathematics and Statistics of the University of São Paulo (IME-USP), currently visiting NYU Shanghai and working with Roberto Fernández.

My research lies in rigorous statistical mechanics and probability. I am particularly interested in phase transitions and correlation decay in long-range spin systems, contour and cluster-expansion methods, and mathematical approaches to equilibrium in quantum spin systems.

I received my PhD in Applied Mathematics from the University of São Paulo. My doctoral work developed multiscale contour methods for long-range Ising models and a boundary-condition approach to quantum statistical mechanics.


Research themes

Long-range spin systems

Phase transitions, contour representations, cluster expansions, random fields, decaying external fields, and algebraic decay of correlations.

Quantum equilibrium

Boundary conditions for quantum spin systems, quantum analogues of DLR specifications, KMS states, and groupoid and probabilistic representations.

Selected work

Long-Range Ising Models: Contours, Phase Transitions and Decaying Fields

With R. Bissacot, E. O. Endo, and S. Handa. Journal of the European Mathematical Society 27 (2025), 1679–1714.

Journal · arXiv

Cluster Expansion and Decay of Correlations for Multidimensional Long-Range Ising Models

With R. Bissacot, J. Maia, J. F. Rodrigues, and K. Welsch.

arXiv

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