|Title||Emergent phenomena in large interacting ecosystems|
|Speaker||Giulio BIROLI (Institute for Theoretical Physics CEA Saclay)|
📅 March 21, 2018 (Wednesday)
|Location||SISSA, Ground Floor, Room 5|
I will first start with a general introduction on theoretical ecology, stressing the reasons that make connections with statistical physics interesting and timely.
I will then focus on Lotka–Volterra equations, which provide a general model to study large assemblies of strongly interacting degrees of freedom in many different fields: biology, economy and in particular ecology. I will present our analysis of Lotka–Volterra equations as model of ecosystems formed by a large number of species and show the different phases that emerge. Two of them are particularly interesting: when interactions are symmetric we find a regime characterised by an exponential number of multiple equilibria, all poised at the edge of stability for a large number of species. For non symmetric interactions, this phase is replaced by a chaotic one. I will then conclude discussing relationships with experiments and general consequences of our works.
|Title||Matrix product states for relativistic quantum gauge field theories|
|Speaker||Karel VAN ACOLEYEN (Gent)|
📅 March 27, 2018 (Tuesday)
|Location||ICTP, Leonardo Building, First Floor, Luigi Stasi Seminar Room|
|Abstract||In this talk I will describe our work on the simulation of the Schwinger model (i.e. d=1+1 QED) with matrix product states (MPS). I will discuss some systematic aspects of our approach like the truncation of the local infinite bosonic gauge field Hilbert space, or the incorporation of local gauge invariance into the MPS ansatz. Furthermore, I will go through some of our results: the simulation of the particle excitations (“mesons” of confined electron/positron pairs), of string breaking for heavy probe charges and last but not least of the real-time evolution that occurs from a background electric field quench (i.e. the full quantum Schwinger effect).|
|🔗 Past seminars|