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  • Open Access

Topological defects as effective dynamical dark energy

Haipeng An1,2,*, Chengcheng Han3,4,†, and Borui Zhang1,‡

  • *Contact author: anhp@mail.tsinghua.edu.cn
  • †Contact author: hanchch@mail.sysu.edu.cn
  • ‡Contact author: zhangbr22@mails.tsinghua.edu.cn
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Phys. Rev. D 113, 043543 – Published 24 February, 2026

DOI: https://doi.org/10.1103/2m4c-1zl5

Abstract

In this work, we consider the possibility that the dynamical dark energy hinted at by recent Dark Energy Spectroscopic Instrument data may be mimicked by the effects of additional components in the universe, potentially arising from topological defects. We find that the data does not show a particular preference for the existence of cosmic strings. However, a domain wall contribution at the percent level can improve the fit, yielding a Δχ2=−1.72 and ΔDIC=−0.94 compared to the lambda-cold dark matter model (ΛCDM). The improvement indicates that topological defects remain a viable and interesting extension to ΛCDM, meriting further investigation with future cosmological data.

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Phys. Rev. D 113, 043543– Published 24 February, 2026
  • Received 12 September 2025
  • Accepted 30 January 2026
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