Events at Physics |
Events on Friday, October 16th, 2026
- Physics Department Colloquium
- Neutron Stars Are Plastic
- Time: 3:30 pm - 4:30 pm
- Place: Chamberlin 2241
- Speaker: Matt Caplan, Illinois State University
- Abstract: Neutron star crusts are weird. They are fully ionized plasmas of nuclei at densities reaching 10^14 g/cm^3, but under such high pressure that they freeze into a crystal solid. The elastic properties of this solid are especially important for understanding crust breaking and transients in magnetar outbursts and starquakes, but this material cannot break like terrestrial solids due to the high pressure suppressing the formation of fractures and voids. Fortunately, large scale molecular dynamics simulations make it possible to study breaking, plastic flow, and other behavior beyond linear elasticity. I will present our new molecular dynamics simulations demonstrating that neutron star crusts likely have very simple elastic-perfectly plastic rheology, with many strong analogs to terrestrial materials. If perfect crusts experience brittle failure and flow plastically before reannealing, it's possible that neutron star crusts experience 'cycling' with implications for magnetar outbursts.
- Host: Vladimir Zhdankin