Shadow and observational images of the rotating Hayward black hole with thin disk accretion

We investigate the shadow and observational characteristics of rotating Hayward black holes by employing a ray-tracing method combined with stereographic projection. By solving the photon geodesics derived from the Hamilton–Jacobi equation, we explore how the spin parameter a and magnetic charge g influence the shape of the black hole shadow and its observable optical properties. The results indicate that an increase in the spin parameter a leads to a pronounced D-shaped deformation of the shadow, whereas higher values of the magnetic charge g significantly reduce the size of its inner region. When a thin accretion disk surrounds the black hole, variations in a and g directly affect observable features, including the size of the inner shadow and the intensity of the emitted radiation. Furthermore, the direct and lensed images exhibit distinct redshift features, highlighting the strong sensitivity of gravitational lensing effects to the parameters a and g. These findings suggest that rotating Hayward black holes can be distinguished from Kerr black holes through their observable characteristics, thereby providing a valuable reference for testing alternative theories of gravity.