The paper by Hamsa Padmanabhan and Abraham Loeb explores the implications of recent data from the James Webb Space Telescope (JWST) and the NANOGrav Pulsar Timing Array (PTA) on the evolution and feedback mechanisms of supermassive black hole binaries (SMBHs). The authors use JWST data to investigate the fraction of dual active galactic nuclei (AGN) at $z \sim 3.4$, which is significantly higher than expected based on current simulations. This suggests that the dual AGN members are 'lit' simultaneously, indicating that gas-rich mergers are responsible for concurrent AGN activity. The NANOGrav PTA measurements provide upper limits on the stochastic gravitational wave (GW) strain amplitude, which are below those expected from extrapolating the dual AGN fraction. This supports the idea that either the binaries are stalled at separations probed by NANOGrav, or they are undergoing rapid gas-driven inspirals. The authors also discuss the 'final parsec' problem, where binaries may stall due to the lack of stars or gas in their vicinity, or the possibility of rapid inspirals driven by gas. The paper concludes that the high fraction of dual AGN observed by JWST, combined with the NANOGrav data, provides evidence for either a 'stalling' of binaries at separations probed by NANOGrav or rapid gas-driven inspirals. These findings have implications for understanding the evolution and feedback mechanisms of SMBHs, particularly in the context of gas-rich mergers and the 'final parsec' problem.The paper by Hamsa Padmanabhan and Abraham Loeb explores the implications of recent data from the James Webb Space Telescope (JWST) and the NANOGrav Pulsar Timing Array (PTA) on the evolution and feedback mechanisms of supermassive black hole binaries (SMBHs). The authors use JWST data to investigate the fraction of dual active galactic nuclei (AGN) at $z \sim 3.4$, which is significantly higher than expected based on current simulations. This suggests that the dual AGN members are 'lit' simultaneously, indicating that gas-rich mergers are responsible for concurrent AGN activity. The NANOGrav PTA measurements provide upper limits on the stochastic gravitational wave (GW) strain amplitude, which are below those expected from extrapolating the dual AGN fraction. This supports the idea that either the binaries are stalled at separations probed by NANOGrav, or they are undergoing rapid gas-driven inspirals. The authors also discuss the 'final parsec' problem, where binaries may stall due to the lack of stars or gas in their vicinity, or the possibility of rapid inspirals driven by gas. The paper concludes that the high fraction of dual AGN observed by JWST, combined with the NANOGrav data, provides evidence for either a 'stalling' of binaries at separations probed by NANOGrav or rapid gas-driven inspirals. These findings have implications for understanding the evolution and feedback mechanisms of SMBHs, particularly in the context of gas-rich mergers and the 'final parsec' problem.