Abstract
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 param-eters,specifically wall tension around σDW～(29-414 TeV)3 and wall-decay temperature within Td～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(fp,T0)h2～Ωradh2(ΩvΔNeff)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.
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