Probing Graviton Mass with MeerKAT PTA and SKA-PTA Forecasts
Abstract
In this study, we derive constraints on the graviton mass using the 4.5-year data release from the MeerKAT Pulsar Timing Array (MPTA) and provide forecasts for the upcoming Square Kilometre Array PTA (SKA-PTA). By modeling the modified dispersion relation and the corresponding tensor correlation function for massive gravitons, we perform Bayesian inference on the angular-correlation measurements under three noise configurations. Our 90\% credible upper limits on the graviton mass span mg < (2.10-2.58) × 10−23 eV/c2. Including monopolar and dipolar contributions does not significantly alter these bounds, confirming that the constraints are driven by the quadrupolar tensor correlation. All results remain fully consistent with general relativity. For SKA-PTA, we forecast sensitivities down to mg ∼ 10−24 eV/c2 with a 10-year observing baseline and mg ∼ 10−25 eV/c2 with a 50-year observing baseline, representing order-of-magnitude improvements over current limits. This work demonstrates the power of current and future PTA observations to test fundamental aspects of gravity in the nanohertz band.
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BibTeX
@misc{zhao2026probing,
title = {{Probing Graviton Mass with MeerKAT PTA and SKA-PTA Forecasts}},
author = {Zhi-Chao Zhao and Sai Wang},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2607.14790},
eprint = {2607.14790},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.14790},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - Probing Graviton Mass with MeerKAT PTA and SKA-PTA Forecasts
AU - Zhi-Chao Zhao
AU - Sai Wang
PY - 2026
DA - 2026/10/24
PB - arXiv
DO - 10.48550/arxiv.2607.14790
UR - https://arxiv.org/abs/2607.14790
AB - In this study, we derive constraints on the graviton mass using the 4.5-year data release from the MeerKAT Pulsar Timing Array (MPTA) and provide forecasts for the upcoming Square Kilometre Array PTA (SKA-PTA). By modeling the modified dispersion relation and the corresponding tensor correlation function for massive gravitons, we perform Bayesian inference on the angular-correlation measurements under three noise configurations. Our 90\% credible upper limits on the graviton mass span m_g < (2.10-2.58) × 10^−23 eV/c^2. Including monopolar and dipolar contributions does not significantly alter these bounds, confirming that the constraints are driven by the quadrupolar tensor correlation. All results remain fully consistent with general relativity. For SKA-PTA, we forecast sensitivities down to m_g ∼ 10^−24 eV/c^2 with a 10-year observing baseline and m_g ∼ 10^−25 eV/c^2 with a 50-year observing baseline, representing order-of-magnitude improvements over current limits. This work demonstrates the power of current and future PTA observations to test fundamental aspects of gravity in the nanohertz band.
ER -