The Impact of a Midband Gravitational Wave Experiment On Detectability of Cosmological Stochastic Gravitational Wave Backgrounds
(University of California, Riverside)
I will discuss the impact of a future midband gravitational wave experiment on improving detectability of a cosmologically sourced stochastic GW background. Specific proposed midband experiments considered are TianGo, B-DECIGO and AEDGE. We propose a combined power-law integrated sensitivity (CPLS) curve combining GW experiments over different frequency bands, which shows significant improvement in sensitivity to SGWBs with the aid of a midband experiment. We consider GW emission from cosmic strings and phase transitions as benchmark examples of cosmological SGWBs. We explicitly model various astrophysical SGWB sources, most importantly from unresolved black hole mergers. Based on analysis using Markov Chain Monte Carlo, we demonstrated that midband experiments can, when combined with LIGO A+ and LISA, can significantly improve sensitivities to cosmological SGWBs and better separate them from astrophysical SGWBs.