Cosmology-Independent Photon Mass Limits from Localized Fast Radio Bursts by Using Artificial Neural Networks  

作　　者：冉景遇 王宝 魏俊杰 Jing-Yu Ran;Bao Wang;Jun-Jie Wei(Purple Mountain Observatory,Chinese Academy of Sciences,Nanjing 210023,China;School of Astronomy and Space Sciences,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]Purple Mountain Observatory,Chinese Academy of Sciences,Nanjing 210023,China [2]School of Astronomy and Space Sciences,University of Science and Technology of China,Hefei 230026,China

出　　处：《Chinese Physics Letters》2024年第5期177-183,共7页中国物理快报（英文版）

基　　金：supported by the National SKA Program of China (2022SKA0130100);the National Natural Science Foundation of China (Grant Nos. 12373053, 12321003, and 12041306);the Key Research Program of Frontier Sciences of Chinese Academy of Sciences (Grant No. ZDBSLY-7014);the International Partnership Program of Chinese Academy of Sciences for Grand Challenges (Grant No. 114332KYSB20210018);the CAS Project for Young Scientists in Basic Research (Grant No. YSBR-063);the CAS Organizational Scientific Research Platform for National Major Scientific and Technological Infrastructure: Cosmic Transients with FAST;the Natural Science Foundation of Jiangsu Province (Grant No. BK20221562)。

摘　　要：A hypothetical photon mass m_(γ) can produce a frequency-dependent vacuum dispersion of light, which leads to an additional time delay between photons with different frequencies when they propagate through a fixed distance. The dispersion measure and redshift measurements of fast radio bursts(FRBs) have been widely used to constrain the rest mass of the photon. However, all current studies analyzed the effect of the frequency-dependent dispersion for massive photons in the standard ΛCDM cosmological context. In order to alleviate the circularity problem induced by the presumption of a specific cosmological model based on the fundamental postulate of the masslessness of photons, here we employ a new model-independent smoothing technique, artificial neural network(ANN), to reconstruct the Hubble parameter H(z) function from 34 cosmic-chronometer measurements.By combining observations of 32 well-localized FRBs and the H(z) function reconstructed by ANN, we obtain an upper limit of m_(γ) ≤ 3.5 × 10^(-51)kg, or equivalently m_(γ) ≤ 2.0 × 10^(-15)eV/c^(2)(m_(γ) ≤ 6.5 × 10^(-51)kg, or equivalently m_(γ) ≤ 3.6 × 10^(-15)eV/c_(2)) at the 1σ(2σ) confidence level. This is the first cosmology-independent photon mass limit derived from extragalactic sources.

关 键 词：DISPERSION LIMIT INDEPENDENT 

分 类 号：P159[天文地球—天文学] P16