Gravity doesn't always hide the heart of a dying star ⚡ экспресс
An analysis of the role of higher Lovelock curvatures in the collapse of a dust spherical cloud is performed. It is shown that such terms do not restore local cosmic censorship, but rather promote local visibility of central singularities. In the branch with a positive leading Lovelock coefficient c_N, the order N governs the near-singularity collapse and the formation of trapped surfaces. In non-critical dimensions (D-1-2N>0), the apparent horizon curve approaches the singularity curve with a trapping exponent β_N=(D-1)/(D-1-2N); the local visibility condition is ℓ<β_N for an outward-opening singularity curve and a first-order correction r^ℓ. As N increases, the class of inhomogeneous initial data giving rise to outgoing rays from the center expands. In the critical case D=2N+1, the apparent horizon does not form near the center, and any opening of the singularity curve yields visibility. The singularities are Krolak-strong along the rays, and Tipler-strength is achieved at the threshold. The energy function influences the opening of the curve in the non-critical case and the final collapse velocity in the critical one.
Ordinary gravity is like soft rubber. A dying massive star bends it so deeply that it forms a black hole — a trap from which nothing, not even light, escapes. Physicist Roger Penrose suggested that nature always hides the core behind such 'cosmic censorship'.
However, in a new study, scientists considered a case where spacetime behaves like a very springy rubber. Adding stiffness to the equations of gravity, they found: the star still collapses, but the membrane doesn’t seal into an impenetrable sack. Light from the center bursts out. Imagine a trampoline: a heavy ball pushes it down, but if the trampoline is too tight, the edges don’t meet, and the ball remains visible.
Such 'naked' cores aren't just an abstraction. They could reveal themselves through bursts of gravitational waves or particles, allowing astronomers to peer into the world of quantum gravity. Strikingly, the mathematical additions that stiffen the rubber appear naturally in string theory — perhaps this is happening in the real Universe.
🎯 Penrose, a Nobel laureate, coined the term 'cosmic censorship' in 1969, but now his hypothesis is challenged in theories with extra spacetime stiffness.