Cosmological moduli problem ameliorated by decaying WIMPs
Abstract
We investigate the cosmological moduli problem (CMP) in the context of supersymmetric models where discrete R-symmetries are used to suppress the mu term, and where mu is regenerated via Kim--Nilles superpotential operators. In such theories, a global U(1)_{PQ} emerges as an accidental, approximate symmetry which solves the strong CP problem. R-parity is also generated as accidental but approximate, where RPV operators gain a (f_a/m_P)^n suppression. When n=1, the thermally-produced LSPs may decay before BBN in the early universe, leaving axion-only dark matter of the SUSY DFSZ type. Meanwhile, the dominant cosmological constraint on light stringy moduli previously came from the modulus-induced WIMP overproduction problem. WIMP overproduction is now ameliorated by the RPV WIMP decays, but the moduli-induced BBN bound may be exacerbated by convolving long-lived modulus decay with long-lived RPV WIMP decay: long-lived particle (LLP) cascade decays. In this context, moduli as light as m_ϕ~ 130 TeV may be allowed which can reconcile naturalness with the presence of stringy moduli in the early universe.
Related
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- Fermi-eROSITA cross-correlations suggest annihilation lines of ∼70 GeV WIMPs
BibTeX
@misc{baer2026cosmological,
title = {{Cosmological moduli problem ameliorated by decaying WIMPs}},
author = {Howard Baer and Vernon Barger and Robert Wiley Deal},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.04412},
eprint = {2609.04412},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.04412},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Cosmological moduli problem ameliorated by decaying WIMPs
AU - Howard Baer
AU - Vernon Barger
AU - Robert Wiley Deal
PY - 2026
DA - 2026/09/03
PB - arXiv
DO - 10.48550/arxiv.2609.04412
UR - https://arxiv.org/abs/2609.04412
AB - We investigate the cosmological moduli problem (CMP) in the context of supersymmetric models where discrete R-symmetries are used to suppress the mu term, and where mu is regenerated via Kim--Nilles superpotential operators. In such theories, a global U(1)_{PQ} emerges as an accidental, approximate symmetry which solves the strong CP problem. R-parity is also generated as accidental but approximate, where RPV operators gain a (f_a/m_P)^n suppression. When n=1, the thermally-produced LSPs may decay before BBN in the early universe, leaving axion-only dark matter of the SUSY DFSZ type. Meanwhile, the dominant cosmological constraint on light stringy moduli previously came from the modulus-induced WIMP overproduction problem. WIMP overproduction is now ameliorated by the RPV WIMP decays, but the moduli-induced BBN bound may be exacerbated by convolving long-lived modulus decay with long-lived RPV WIMP decay: long-lived particle (LLP) cascade decays. In this context, moduli as light as m_ϕ~ 130 TeV may be allowed which can reconcile naturalness with the presence of stringy moduli in the early universe.
ER -