Bubbleparticle

Bubbleparticle is a hypothetical particle concept used in some speculative discussions of quantum field theory and cosmology to describe a localized excitation associated with bubble-like structures that can form during first-order phase transitions or false-vacuum decay. It is not part of the standard model, and there is no experimental evidence for its existence.

In theoretical setups, bubbles arise when a metastable vacuum decays to a more stable phase. As bubbles nucleate and walls propagate, certain bound states or collective excitations of fields confined to or propagating along the bubble wall can behave like discrete particles. Bubbleparticles, if they exist, would be model-dependent and may differ in mass, spin, and interaction strength according to the specifics of the underlying field theory and the properties of the bubble wall.

Possible characteristics attributed to bubbleparticles include weak or hidden-sector couplings to Standard Model fields, localization on the bubble boundary, and dispersion relations tied to the dynamics of the wall. Some models allow bubbleparticles to carry energy along the wall, interact with bubble collisions, or influence the evolution of the phase transition. Their lifetimes could vary from transient to potentially stable within a given theoretical framework.

Experimental prospects for bubbleparticles are uncertain and highly model-dependent. Potential indirect signatures include imprints on the stochastic gravitational wave background from cosmological phase transitions, or subtle effects on early-universe dynamics. Direct detection would require identifying specific couplings or production mechanisms predicted by a concrete theory.

See also: false vacuum decay, bubble nucleation, solitons, topological defects, phase transitions in the early universe.