Shadows of rotating black holes with parity-odd scalar hair

Abstract: Strong self-gravitational fields enable the realization of macroscopic odd-parity quantum objects. Using ray-tracing methods, we systematically analyze the shadow features of rotating black holes with parity-odd scalar hair and contrast them with those of Kerr black holes. Our results demonstrate measurable distinctions between scalar-haired black hole shadows and their Kerr counterparts. Notably, even for tiny scalar charge and negligible scalar hair mass contributions, these differences remain quantitatively resolvable. These findings provide critical theoretical benchmarks for future observational campaigns targeting scalar-field dark matter candidates through black hole shadow imaging.