AI-rewritten: This is a summary of an article from Phys.org, rewritten by AI (Qwen, running locally) to make it easier to read. The facts come from the original article – read it for the full story.

---

Three researchers have calculated how three different quantum gravity models affect the sound a black hole makes after merging. In Einstein’s standard theory, gravity has a fixed strength everywhere. However, some quantum theories suggest gravity changes depending on distance. The team found that if gravity weakens at very short distances, the resulting black hole rings at a higher pitch and for a longer time. Conversely, if gravity strengthens near the center, the black hole rings at a lower pitch and fades away more quickly.

The study compared three specific models: one where gravity grows stronger near the core, creating a spread-out singularity; one based on asymptotic safety where gravity switches off completely, creating a smooth inner horizon; and a third model where two horizons can merge. Using advanced mathematical methods instead of standard shortcuts, the team computed these tones with extreme precision. They found that at their most extreme points, the Hayward black hole rings 9.5% higher and lasts 28% longer than Einstein’s prediction, while the Planck star model rings 25.0% lower and fades 21.6% faster.

Although current detectors cannot hear these sounds from large black holes like the sun, the results provide a clear map of how hidden centers leave fingerprints. The findings suggest that if gravity weakens near the center, it creates a "better bell," while stronger gravity makes a duller one. These precise tables of tones are now available for others to use, offering a way to distinguish between different quantum theories based on the unique vibration patterns they predict.