Close Pulsar Pairs See Dark Matter Substructure through the Gravitational-Wave Background
Abstract
Pulsar timing arrays detect signals from dark matter substructure, but a nanohertz gravitational-wave background (GWB) severely degrades their sensitivity. We show that timing pulsar pairs separated by sub-parsec distances avoids this degradation. The GWB imprints nearly the same perturbation on both pulsars and is suppressed in the difference of their residuals, whereas a nearby dark matter subhalo perturbs the two differently and survives. We find that an array with pulsar pairs separated by 0.1 pc improves the sensitivity to subhalos of order ∼10−6 solar masses by more than an order of magnitude, relative to an otherwise identical array of widely separated pulsars. Dense globular clusters naturally host many such pairs, though the baryonic environment must be separated from a dark matter substructure signal.
Related
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BibTeX
@misc{cherukupalli2026close,
title = {{Close Pulsar Pairs See Dark Matter Substructure through the Gravitational-Wave Background}},
author = {Abhiram Cherukupalli and Vincent S. H. Lee and Kim V. Berghaus and Kathryn M. Zurek},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.38305},
eprint = {2609.38305},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.38305},
}
RIS
TY - UNPB
TI - Close Pulsar Pairs See Dark Matter Substructure through the Gravitational-Wave Background
AU - Abhiram Cherukupalli
AU - Vincent S. H. Lee
AU - Kim V. Berghaus
AU - Kathryn M. Zurek
PY - 2026
DA - 2026/09/29
PB - arXiv
DO - 10.48550/arxiv.2609.38305
UR - https://arxiv.org/abs/2609.38305
AB - Pulsar timing arrays detect signals from dark matter substructure, but a nanohertz gravitational-wave background (GWB) severely degrades their sensitivity. We show that timing pulsar pairs separated by sub-parsec distances avoids this degradation. The GWB imprints nearly the same perturbation on both pulsars and is suppressed in the difference of their residuals, whereas a nearby dark matter subhalo perturbs the two differently and survives. We find that an array with pulsar pairs separated by 0.1 pc improves the sensitivity to subhalos of order ∼10^−6 solar masses by more than an order of magnitude, relative to an otherwise identical array of widely separated pulsars. Dense globular clusters naturally host many such pairs, though the baryonic environment must be separated from a dark matter substructure signal.
ER -