Echoes from charged black holes influenced by quintessence

In this paper, we investigate the effective potential and echoes from dyonic black holes with quintessence. For a dyonic black hole, the quasi-topological electromagnetism provides proper matter energy-momentum tensor to curve the spacetime, and quintessence strengthens this force. We find that when the effect of quintessence becomes stronger, the black hole potential will experience a series of complex transition processes between single-peak and double-peak. This causes repeated appearance and disappearance of the black hole echoes. In particular, we find that observer will receive a sudden vanishment of high-frequency echoes when quintessence remains a relatively strong effect.