Logo CNRS Logo Université Paris Diderot
Logo tutelle Logo tutelle


Sur ce site

Sur le Web du CNRS

Startseite > Seminars > Séminaires théorie > Theory Club Wednesday March 11 2020 at 12:00 in room 412B. Yerali Gandica: "Bali ancient rice terraces: A Hamiltonian approach".

Theory Club Wednesday March 11 2020 at 12:00 in room 412B. Yerali Gandica: "Bali ancient rice terraces: A Hamiltonian approach"

Unless otherwise stated, seminars and defences take place at 11:30 in room 454A of Condorcet building.

Bali ancient rice terraces: A Hamiltonian approach

Yerali Gandica

Abstract: In this talk, I will present a Hamiltonian approach inspired by the Subak irrigation system. In a previous work, Lansing et al. [1] found out that the cluster-size distribution of the rice patches in Bali-Subak fields is a power-law function with an exponent (approx. 1.9) similar to the one found on Hamiltonian systems. The application of the methods of statistical physics to social phenomena, where the interacting particles are now interacting human beings, has proved to be very fruitful in allowing for the understanding of many features of human behaviour. In this sense, Universality, which states that the emergent phenomena displayed by the collective behaviour of interacting particles depend on symmetries, dimensionality and conservation laws and not on the microscopic details of the intrinsic dynamics mechanism, seems to be present in many social situations. I will show how the beautiful mosaics characterising several rice-growing regions in Bali- Indonesia, which are the consequence of the self-organising process ruled by the Subak since the 11th century in that tropical island, can be explained by two main mechanisms behind Subak farmers’ decisions. Pest stress is the local mechanism promoting order, namely, using the same schedule within neighbouring patches. On the other hand, an antiferromagnetic interaction controlled by water stress is set by a global mechanism, fixing a limit in the total number of cells in the same state. Our Subak Hamiltonian presents two phase transitions, one of them having a critical nature. I will present our first results, general conclusions and consequences of scaping from that critical balance. For the talk, first, I will briefly explain my research line, second my current works, and finally, the Hamiltonian approach.

References [1] Adaptive self-organization of Balinese subaks. J. Stephen Lansing, Stefan Thurner, Ning Ning Chung, Aurlie Coudurier-Curveur, ail Karaka, Kurt A. Fesenmyer, and Lock Yue Chew. PNAS, 114 (25) 6504-6509.

Wednesday March 11 at 12:00 in room 412B

Contact : Équipe séminaires / Seminar team - Published on / Publié le 6 March 2020

In the same section :