SciPost Phys. 13, 049 (2022) ·
published 2 September 2022
We study false vacuum decays catalysed by magnetic monopoles which act as
tunnelling sites with exponentially enhanced decay rates. The field profiles
describing the decay do not have the typically assumed $O(3)/O(4)$ symmetry,
thus requiring an extension of the usual decay rate calculation. To numerically
determine the saddle point solutions which describe the tunnelling process we
use a new algorithm based on the mountain pass theorem. This method can be
applied more widely to phase transitions with reduced symmetry, such as decays
away from the zero and infinite temperature limits. Our results show that
monopole-catalysed tunnelling can dominate over the homogeneous false vacuum
decay for a wide range of parameters, significantly modify the gravitational
wave signal or trigger phase transitions which would otherwise never complete.
A single boring monopole in our Hubble patch may determine the lifetime of the
Standard Model vacuum.