Pc(4312), Pc(4380), and Pc(4457) as double triangle cusp
I discuss a novel scenario for the pentaquark-like signals in the LHCb data. I identify double triangle mechanisms with kinematical singularities. I demonstrate that the double triangle amplitudes reproduce the peak structures of $P_c(4312)$, $P_c(4380)$, and $P_c(4457)$, through an interference with other common mechanisms. Only the $P_c(4440)$ peak is due to a resonance with width and strength significantly smaller than the previous LHCb estimate. The reference is PRD 103, L111503 (2021).