Fig. 1: Illustration, model, and dispersion properties of a black hole-inspired ρ-ABH metamaterial.
From: Deep-subwavelength ultra-low and ultra-broadband acoustic-black-hole metamaterials
a Schematical diagram of the black hole in astronomy. The red arrow depicts the trajectory of light that cannot escape the black hole’s event horizon. b Schematical diagram of the proposed ρ-ABH. c The reduced-order model of the ρ-ABH. d–g Dispersion curves of the ρ-ABH: real and imaginary parts of Ki (i = 1, …, 4) are plotted versus the dimensionless wavenumber Kf x0.
