Chaos and Nonlinearity in Dynamical Astronomy
IFPU
23 – 27 February 2026
The dynamical evolution of gravitationally interacting bodies, from the planetary systems to cosmological scales, is largely governed by nonlinear phenomena resulting from the inherently chaotic nature of the gravitational N-body problem for N>2. Historically, studies of the few-body problem (typically N~10), fundamental in celestial mechanics, have relied predominantly on perturbative methods. Conversely, for larger N typical of galactic dynamics, the theoretical frameworks of kinetic theory and statistical physics, approaches also prevalent in plasma physics, have been the primary tools. Despite extensive efforts within these two most often separate communities, numerous fundamental questions remain unresolved. Key open questions include: how does the intrinsic chaos of the gravitational N-body problem affect the long-term stability of astrophysical equilibrium configurations? Are chaotic phenomena in galaxy evolution driven primarily by discrete particle interactions and close encounters, or are perturbations in the collective gravitational potential more influential? Furthermore, do relativistic effects in multiple systems of compact objects act as stabilizing factors, or do they amplify their chaotic behavior? This Focus Week aims at addressing these questions through a multi-disciplinary approach, bridging gaps between celestial mechanics, galactic dynamics, and statistical physics.
Meeting program: https://sites.google.com/view/chaos-and-nonlinearity/home
Organisers:
- Alessandro Trani (University of Concepción)
- Pierfrancesco Di Cintio (CNR-ISC, Firenze)
- Mario Spera (SISSA, Trieste)
Participants:
- Lucy Arditi (University of Edinburgh)
- Tjarda Boekholt (Amsterdam University)
- Filippo Bucci (University of Bologna)
- Roberto Capuzzo-Dolcetta (University of Rome, la Sapienza)
- Lapo Casetti (University of Florence)
- Giulia Congera (University of Bologna)
- Jérôme Daquin (CPT, University of Toulon)
- Stefano Disca (University of Ferrara)
- Pierfrancesco Di Cintio (CNR-ISC, Firenze, Italy)
- Christos Efthymiopoulos (University of Padua)
- Jean-Baptiste Fouvry (CNRS-IAP, France)
- Evgeni Grishin (Monash University)
- Toshinori Hayashi (Gunma KOSEN College)
- Barak Kol (Hebrew University of Jerusalem, Israel)
- Nathan Leigh (University of Concepción)
- Ugo Locatelli (Università di Roma Tor Vergata)
- Rosemary Mardling (Monash University)
- Federico Mogavero (University of Padova)
- Simon Portegies Zwart (Leiden University)
- Stefano Ruffo (SISSA, Trieste & CNR-ISC, Florence)
- Charalampos Skokos (University of Cape Town)
- Yasushi Suto (Kochi University)
- Alessandro Trani (University of Concepción, Chile)
- Anna Lisa Varri (University of Edinburgh)
- Eugene Vasiliev (University of Surrey)