Comportements collectifs B04
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From molecules to galaxies, we observe some entities (atom, cell, individual or star) that interact together by attraction and/or repulsion and from these local interactions emerge a global structure, organised and complex, having its own characteristics.
According to the different forces impacting the interactions between entities, the global structure/system can be more or less cohesive (spatial) and/or stable (temporal).
The different systems can also be connected together by some entities. These entities allows some exhcanges between the different systems (matter between galaxies, information or genes between groups). These exchanges of genes or new matters (new atoms) give new properties to one or both of the systems.
These interactions between the different systems and the new methodologies measuring them bring some issues about how to define these systems as own entities (animal group, galaxy, etc.). Some entities make the connection between two structures, or two structures are fusing or are fissioning, we do not know when the two entities become one or the one becomes two.
Challenges:
1. When fusing, stars into galaxies can be see like birds or fishes into flocks or schoals. Three rules can be designed: alignment, maximum distance (cohesion, to avoid separation) and miminal distance (to avoid collision). Other self-organized rules were found in animals such as in ants to find the best food source or in primates to move collectively. The rules that are applied at this level seems to be the same than the ones that are applied at the neural networks (such as the diffusion model allowing optimal decisions) or at the molecular level (with amplification effect, snow-ball effect or feedback loop). It might be interesting to find the rules underlying all these collective behaviours of these different entities and that allow the emergence of complex systems (molecules, organisms, animal groups, ecosystems and galaxies). According to the Parcimony principle, we should find rules simple and similar between these different systems and conclude about the universality of collective behaviours and decision rules, whatever the nature of the complex system and of its entities.
2. Definition of coherence (spatio-temporal integrity), stability (temporal, ESS) and cohesion (spatial, diffusion, fission-fusion dynamics, segregation) of the different complex systems defined here.
Stars may display some spatial segregation with large and old stars at the center of a core as it is found in primates with top-ranking individuals in the middle of the group and low-ranking ones at the group periphery.
3. common methodology (diffusion models, common algorythms, graphs and dynamics thereon) and bridging the gap between all disciplines (from physics to biology to ecology and astrophysics; i.e. knowledge about each discipline and between each discipline)
4. new methods of simulation avoiding or controlling numerical diffusion
Participants : Cédric Sueur, Paul Bourgine, Stella Marc-Zwecker, Nicolas Rivier, Hervé Wozniak
Keywords :
- Object (ceci est un exemple, à adapter pour l'objet du groupe de travail)
- F1 - Ecosystème Galactique (from stars to galaxies)
- F1 - Groupe/Population animale (from individuals to groups and populations)
- F1 - Organisme (from cells to organisms)
- F1 - Molecule (from atoms to molecules)
- Challenges
- F1 - Self-organization and parcimony or rules
- F1 - Coherence of complex systems
- F1 - Common methodology and linking disciplines
- F1 - new methods of simulation avoiding numerical diffusion
Cédric Sueur, Paul Bourgine, Stella Marc-Zwecker, Nicolas Rivier, Hervé Wozniak