Production of dark matter axions from collapse of string-wall systems

By Takashi Hiramatsu, M. Kawasaki, K. Saikawa, Toyokazu Sekiguchi. 2012

224 citations recorded by the source corpus.

We analyze the spectrum of axions radiated from collapse of domain walls, which have received less attention in the literature. The evolution of topological defects related to the axion models is investigated by performing field-theoretic lattice simulations. We simulate the whole process of evolution of the defects, including the formation of global strings, the formation of domain walls and the annihilation of the defects due to the tension of walls. The spectrum of radiated axions has a peak at the low frequency, which implies that axions produced by the collapse of domain walls are not highly relativistic. We revisit the relic abundance of cold dark matter axions and find that the contribution from the decay of defects can be comparable with the contribution from strings. This result leads to a more severe upper bound on the axion decay constant.

View Paper: https://www.semanticscholar.org/paper/b0c358d8067c007e6ab701beac6add47649fc3f2

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1. L. Luzio
2. Maurizio Giannotti
3. K. Saikawa
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5. P. Graham
6. E. Nardi
7. Y. Gouttenoire
8. A. Ringwald

Citations in the corpus

• Freeze-In dark matter with displaced signatures at colliders (2015, background): “If TR is above 160 MeV the entropy generated at the end of the MD era does not dilute the axion density coming from coherent oscillations of the axion field but only the (theoretically uncertain) contribution coming from the decay of topological defects [38–41].”
• Vector Dark Matter from Inflationary Fluctuations (2015, background): “Other mechanisms such as the emission of these particles from topological defects such as strings may yield calculable abundances but are beset with computational challenges [55].”
• The landscape of QCD axion models (2020, background): “In the case of NDW = 1, strings disrupt the DWs soon after their formation by separating them into smaller pieces [197, 243] and dissipating the network whose decay produces a spectrum of radiated axions which also includes a cold axion component that adds up to the axion CDM produced by misalignmen”
• Early seeds of axion miniclusters (2018, methodology): “itons. Recent simulations of the cosmic strings network have been used to compute the total axion DM density, either directly [54,55] or by studying the energy loss from the axion string network, see [56,57] and the particularly recent [58,59]. These works predict dierent values for the axion DM mas”
• Beyond the Standard Models with cosmic strings (2019, background): “However, there are mechanisms which can make the network decay, such as breaking into monopole (M) antimonopole (M) pairs [202–205], Hubble-induced mass of flat direction in supersymmetric theories [206, 207], symmetry restoration in runaway quintessential scenarios [125], or the formation of domain”
• An Introduction to Particle Dark Matter (2019, background): “[48, 72] give the following different values: Ωstrings + domain wallsh 2 = (3.”
• On the estimation of gravitational wave spectrum from cosmic domain walls (2013, methodology): “Hence it would be useful to introduce the scaling parameter (or area parameter) [40, 49] given by A ≡ ρwall σwall t.”
• Stellar recipes for axion hunters (2017, background): “200μeV [62, 76, 77] — way too small to explain the stellar cooling anomalies.”
• The dark-matter axion mass (2017, background): “The conventional wisdom has been (see for instance [28]) that axions are produced by misalignment in the space between walls, by walls, and by strings.”