Phase transitions in the early universe and their signals

Phase transitions, such as the boiling of water or the melting of a metal, are commonplace but fascinating phenomena that spur surprises decades after decades. They occur when the temperature of a substance is changed through the nucleation of bubbles of the new phase. The whole container has been taken over by the new phase.

The universe was made of a hot plasma that cooled as the universe expanded. Physicists theorize that a phase transition may have happened soon after the Big bang. This would lead to nucleation of bubbles. Powerful ripples in spacetime could be seen in the planned detectors. The Laser Interferometer Space Antenna (LISA), with a launch date in 2037, may be able to detect early universe spacetime ripples.

It has been difficult to describe early universe phase transitions. A group of researchers from the University of Helsinki, the University of Oviedo, and the University of Sussex used a string theory to attack the problem. They showed how the duality can be used to map the problem to a more manageable one, and how the important quantities describing the bubble nucleation can be obtained.

In the future these new methods can be applied directly in more realistic scenarios, where the starting point would be a possible extension of the Standard Model of particle physics.

The results were published in a journal. The computation of the bubble wall velocity is one of the last obstacles that needs to be overcome for the full first principles description of the early universe phase transition.

More information: Fëanor Reuben Ares et al, Gravitational Waves at Strong Coupling from an Effective Action, Physical Review Letters (2022). DOI: 10.1103/PhysRevLett.128.131101 Journal information: Physical Review Letters Citation: Phase transitions in the early universe and their signals (2022, April 14) retrieved 15 April 2022 from https://phys.org/news/2022-04-phase-transitions-early-universe.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.