# Self-oscillation

#### Self-oscillation

- Event time: 2:00pm
- Event date: 14th December 2016
- Speaker: Alejandro Jenkins (Universidad de Costa Rica)
- Location: Higgs Centre Seminar Room, Room 4305, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB

### Event details

A self-oscillator generates and maintains a periodic motion at the expense of an energy source with no corresponding periodicity. Small perturbations about equilibrium are anti-damped. Non-linearity accounts for steady-state oscillations and for the ability of coupled self-oscillators to exhibit both spontaneous synchronisation (“entrainment”) and chaos. The theory of self-oscillators has achieved its greatest sophistication in control theory and in the study of ordinary differential equations. I shall explain in this talk how an understanding better suited to the needs of physicists can be founded on considerations of energy, efficiency, and thermodynamic irreversibility.

After reviewing the key differences between forced a parametric resonances on the one hand and self-oscillators on the other, I will comment on how a physical approach to the theory of self-oscillators throws new light on hydrodynamic instabilities. I will close by describing hydrodynamic and mechanical analogs of the Zel’dovich superradiance of rotating black holes, a subject of considerable interest in high-energy physics today.

### About Particle Physics Theory seminars

The Particle Physics Theory seminar is a weekly series of talks reflecting the diverse interests of the group. Topics include analytic and numerical calculations based on the Standard Model of elementary particle physics, theories exploring new physics, as well as more formal developments in gauge theories and gravity..