On the quantum stability of Q-balls

  • Anders Tranberg
  • David J. WeirEmail author
Open Access


We consider the evolution and decay of Q-balls under the influence of quantum fluctuations. We argue that the most important effect resulting from these fluctuations is the modification of the effective potential in which the Q-ball evolves. This is in addition to spontaneous decay into elementary particle excitations and fission into smaller Q-balls previously considered in the literature, which — like most tunnelling processes — are likely to be strongly suppressed. We illustrate the effect of quantum fluctuations in a particular model ϕ 6 potential, for which we implement the inhomogeneous Hartree approximation to quantum dynamics and solve for the evolution of Q-balls in 3 + 1 dimensions. We find that the stability range as a function of (field space) angular velocity ω is modified significantly compared to the classical case, so that small-ω Q-balls are less stable than in the classical limit, and large-ω Q-balls are more stable. This can be understood qualitatively in a simple way.


Solitons Monopoles and Instantons Lattice Quantum Field Theory 


Open Access

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© The Author(s) 2014

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits use, duplication, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Authors and Affiliations

  1. 1.Faculty of Science and TechnologyUniversity of StavangerStavangerNorway
  2. 2.Department of Physics and Helsinki Institute of PhysicsUniversity of HelsinkiHelsinkiFinland

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