We explore the possibility that domain wall networks generate the stochastic gravitational wave background(SGWB) observed as a strong common power-law process in the Data Release-2 of Parkes Pulsar Timing Array. We fi...We explore the possibility that domain wall networks generate the stochastic gravitational wave background(SGWB) observed as a strong common power-law process in the Data Release-2 of Parkes Pulsar Timing Array. We find that a broad range of parameters, specifically wall tension around σ_(DW)^(29-414 TeV)^(3) and wall-decay temperature within T_(d) ~ 20-257 MeV, can explain this phenomenon at a 68% credible level. Meanwhile, the same parameters could ease the Hubble tension if particles from these domain wall networks decay into dark radiation. We establish a direct analytical relationship, ΩGW(f_(p), T_(0))h^(2)~ Ω_(rad)h^(2)(Ω_νΩN_(eff))^(2),to illustrate this coincidence, underlining its importance in the underlying physics and potential applicability to a wider range of models and data. Conversely, if the common power-law process is not attributed to domain wall networks, our findings impose tight limits on the wall tension and decay temperature.展开更多
基金supported by the National Key Research and Development Program of China (Grant Nos.2020YFC2201501,and 2021YFC2203004)supported by the National Natural Science Foundation of China (Grant Nos.12075041 and 12147102)+11 种基金supported by the National Natural Science Foundation of China (Grant No.12247147)the International Postdoctoral Exchange Fellowship Programthe Boya Postdoctoral Fellowship of Peking Universitysupported by the National Natural Science Foundation of China (Grant Nos.11963005,and 11603018)Yunnan Provincial Foundation (Grant Nos.2016FD006,and 2019FY003005)Reserved Talents for Young and Middle-aged Academic and Technical Leaders in Yunnan Province ProgramYunnan Provincial High level Talent Training Support Plan Youth Top Programthe National Natural Science Foundation of China (Grant No.11847301)the Fundamental Research Funds for the Central Universities (Grant No.2019CDJDWL0005)supported by Peking Uniersity (Grant No.7101302974)the National Natural Science Foundation of China (Grant Nos.12025507,and 12150015)the Key Research Program of Frontier Science of the Chinese Academy of Sciences (CAS) (Grant No.ZDBS-LY-7003)。
文摘We explore the possibility that domain wall networks generate the stochastic gravitational wave background(SGWB) observed as a strong common power-law process in the Data Release-2 of Parkes Pulsar Timing Array. We find that a broad range of parameters, specifically wall tension around σ_(DW)^(29-414 TeV)^(3) and wall-decay temperature within T_(d) ~ 20-257 MeV, can explain this phenomenon at a 68% credible level. Meanwhile, the same parameters could ease the Hubble tension if particles from these domain wall networks decay into dark radiation. We establish a direct analytical relationship, ΩGW(f_(p), T_(0))h^(2)~ Ω_(rad)h^(2)(Ω_νΩN_(eff))^(2),to illustrate this coincidence, underlining its importance in the underlying physics and potential applicability to a wider range of models and data. Conversely, if the common power-law process is not attributed to domain wall networks, our findings impose tight limits on the wall tension and decay temperature.
