Echoes of charged black-bounce spacetimes

Abstract

Abstract In present work, the evolution of scalar field and electromagnetic field under the background of the charged black-bounce spacetimes are investigated, and we obtain an obvious echoes signal which appropriately reports the properties of the charged black-bounce spacetimes and disclose the physical reasons behind such phenomena. Furthermore, by studying the quasinormal ringdown, we analyze the three states of the charged black-bounce spacetimes in detail, our results show that the echoes signal only appears when $$(|{Q}|\le m)$$ ( | Q | ≤ m ) and $$(|{l}|> m+ \sqrt{m ^{2}-Q^{2} })$$ ( | l | > m + m 2 - Q 2 ) in this spacetime, while when the parameters demand $$(|{Q}|>m)$$ ( | Q | > m ) , the echoes signal will be transformed into a quasinormal ringdown of the two-way traversable wormhole, and the charged black-bounce is a regular black hole with normal horizons by requiring $$(|{Q}|\le m)$$ ( | Q | ≤ m ) and $$(|{l}|< m-\sqrt{m ^{2}-Q^{2} })$$ ( | l | < m - m 2 - Q 2 ) .