Five dimensional rotating regular black holes and shadow

Higher-dimensional theories admit that astrophysical objects like supermassive black holes are somewhat different from standard ones and that their optical properties deviate from general relativity. A black hole casts a shadow as an optical appearance because of its strong gravitational field, and a black hole shadow could be used to determine which theory of gravity is consistent with observations. Measurements of the shadow sizes around the black holes can help evaluate various parameters of the black hole metric and may provide an opportunity to find signatures of extra dimensions. We present an exact five-dimensional (5D) rotating regular black hole metric, with a deviation parameter k >= 0, that interpolates between the 5D Kerr black hole (k = 0) and 5D Kerr-Newman (r >> k). This 5D rotating regular black hole is an exact general relativity solution coupled to nonlinear electrodynamics. Interestingly, for a given value of parameter k, there exits a critical angular momentum a = a(E), which corresponds to an extremal rotating regular black hole with degenerate horizons. At the same time, for a < a(E), one has a non-extremal rotating regular black hole with outer and inner horizons. Owing to the correction factor (e(-k/r2)), which is motivated by the quantum arguments, the ergoregion and shadow of 5D black holes are modified.