Using low redshift data on astrophysical reionization, we report new Lyman-α limit on axion-like particle (ALP) as cold dark matter in ALP mass range of ma∼30−1000 eV. Compared to the Leo T and soft-X ray bound, this limit is so far the most stringent in the ALP mass range of ma∼375−425 eV and complementary in the ALP mass range otherwise. Combing these limits, we show new exclusion limits on ma for the ALP DM from either misalignment or freeze-in mechanism.
@article{arxiv.2410.15675,
title = {Lyman-$\alpha$ limit on axion-like cold dark matter},
author = {Zixuan Xu and Sibo Zheng},
journal= {arXiv preprint arXiv:2410.15675},
year = {2025}
}