We discuss vacuum decays catalyzed by spherical and horizonless objects and show that an ultra compact object could catalyze a vacuum decay around it within the cosmological time. The catalytic effect of a horizonless compact object could be more efficient than that of a black hole since in this case there is no suppression of the decay rate due to the decrement of its Bekestein entropy. If there exists another minimum with AdS vacuum in the Higgs potential at a high energy scale, the abundance of compact objects such as monopoles, neutron stars, axion stars, oscillons, Q-balls, black hole remnants, gravastars and so on, could be severely constrained. We find that an efficient enhancement of nucleation rate occurs when the size of the compact object is comparable to its Schwarzschild radius and the bubble radius.
Oshita, N., Yamada, M., & Yamaguchi, M. (2019). Compact objects as the catalysts for vacuum decays. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 791, 149–155. https://doi.org/10.1016/j.physletb.2019.02.032