Guest Lecture : Kristina Roney
le 13 février 2024
Publié le 26 octobre 2023– Mis à jour le 5 février 2024
Guest Lecture Antonio Politi
Antonio Politi est professeur émérite de physique à l'université d'Aberdeen.
Breathers and transport in statistical systems with two conservation laws
Statistical systems characterized by two conservation laws may exhibit peculiar properties. As an example, the resulting coupled traNsport may induce non monotonous temperature profiles. Furthermore, a region of absolute negative temperatures may arise, characterized by the spontaneous emergence of breather-like solutions accompanied by a progressive coarsening. Last but not least, negative temperatures may spontaneously emerge in the evolution of "standard" nonequilibrium stationary states, while the heat baths operate at positive temperatures.
I'll mostly focus on two systems: the deterministic Discrete NonLinear Schroedinger equation (DNLS) and a stochastic model of non-interacting particles.
In the second setup, theoretical considerations can be carried out and numerical simulations are far more reliable. In particular, general features of the stationary regimes can be determined with the help of linear transport theory. As a result, one can understand the reason why stationary nonequilibrium states may generically enter the negative temperature region.
In the DNLS< The expected scenario is rather similar, but with an important difference: the presence of an adiabatic invariant makes the entire dynamics much slower, in the presence of tall breathers.
Informations pratiques
Statistical systems characterized by two conservation laws may exhibit peculiar properties. As an example, the resulting coupled traNsport may induce non monotonous temperature profiles. Furthermore, a region of absolute negative temperatures may arise, characterized by the spontaneous emergence of breather-like solutions accompanied by a progressive coarsening. Last but not least, negative temperatures may spontaneously emerge in the evolution of "standard" nonequilibrium stationary states, while the heat baths operate at positive temperatures.
I'll mostly focus on two systems: the deterministic Discrete NonLinear Schroedinger equation (DNLS) and a stochastic model of non-interacting particles.
In the second setup, theoretical considerations can be carried out and numerical simulations are far more reliable. In particular, general features of the stationary regimes can be determined with the help of linear transport theory. As a result, one can understand the reason why stationary nonequilibrium states may generically enter the negative temperature region.
In the DNLS< The expected scenario is rather similar, but with an important difference: the presence of an adiabatic invariant makes the entire dynamics much slower, in the presence of tall breathers.
Informations pratiques
- Date : 13 février 2024 de 14h00 à 15h30
- La guest lecture hybride est organisée en présence dans la salle de réunion H008 de la MIR à Neuville-sur-Oise et à distance sur Zoom.
Pour participer à la guest lecture à distance, connectez-vous sur Zoom : https://cyu-fr.zoom.us/j/94353574410
ID réunion : 943 5357 4410 - La vidéo sera publiée sur la chaîne YouTube de CY Advanced Studies.
