I gave a blackboard talk at UKCosmo in May 2019. As I usually like to present movies and other visualisations when giving talks, I have collected that material (and key references and acknowledgments) here instead. The scanned notes for the talk are now available, and the final movies from the project are also online. The paper is also on arXiv.

Collaborators

Our work on strong transitions is in collaboration with Mark Hindmarsh and Daniel Cutting. Earlier work has also involved Stephan J. Huber, Kari Rummukainen, and the broader LISA Cosmology Working Group.

References

• Closely related work by the speaker:

  • arXiv:1705.01783: Gravitational waves from a first order electroweak phase transition: a brief review
  • arXiv:1704.05871: Shape of the acoustic gravitational wave power spectrum from a first order phase transition
  • arXiv:1512.06239: Science with the space-based interferometer eLISA. II: Gravitational waves from cosmological phase transitions
  • arXiv:1504.03291: Numerical simulations of acoustically generated gravitational waves at a first order phase transition
  • arXiv:1304.2433: Gravitational waves from the sound of a first order phase transition

• Papers (probably) mentioned during the talk

  • arXiv:1702.00786 Laser Interferometer Space Antenna
  • LISA 2018 Science Requirements Document [PDF]
  • arXiv:1602.06951 The promise of multi-band gravitational wave astronomy
  • hep-ph/0009132 Electroweak Bubble Nucleation, Nonperturbatively
  • arXiv:1004.4187 Energy Budget of Cosmological First-order Phase Transitions

Visualisations

Generation of vorticity

This movie shows a heatmap of vorticity (\(\nabla \times \mathbf{v}\)) during a strong deflagration (\(\alpha=0.5\), \(v_w=0.44\)). Prepared from preliminary data supplied by Daniel Cutting, it shows several effects mentioned during the talk:

• The bubble walls slow as they get closer to each other.
• Reheated regions form in front of the bubble walls as the fluid kinetic energy gets stuck into smaller spaces.
• Vorticity is generated during the transition, as fluid is forced tangential to the direction of bubble expansion.

These effects are not seen in weaker transitions, or in detonations.

Direct links to video: MP4, webm.

Other visualisations

Please visit my visualisations page or check out the Cosmic Defects channel on Vimeo or YouTube for more.