We studied black holes in gravity theories with extra dimensions. Even an uncharged black hole can't be smaller than a certain mass, and extreme black holes never cool to absolute zero — they stay warm, like an eternally warm kettle. Why is that?
Black holes resemble funnels in a stretched sheet. But if we allow a fifth dimension, the sheet gains hidden springs. Any mass—even uncharged—indents it not to infinity, but to a clear limit. Thus, spacetime curvature gets nonlinear corrections—a new kind of black holes with an innate minimum mass.
And the main surprise: reaching that limit, the hole doesn't cool to absolute zero. Its entropy—a measure of hidden disorder—doesn't vanish, as standard theory would demand. It turns out the universe is strewn with invisible warm cores that hold the memory of hidden dimensions.
🎯 Usually, an uncharged black hole should evaporate completely. But with an extra dimension, it leaves behind a warm, indestructible clot of spacetime.
🎬 It brings to mind 'Interstellar': Gargantua warped time thanks to hidden dimensions. This work makes the science fiction a bit more real.