A Charged Black Hole and Its Evaporating Memory express
A black hole is not an eternal vacuum cleaner. It slowly evaporates, radiating energy, and along with it, as physicists believe, it should return the swallowed information. But when exactly does that start happening? The answer is given by the so-called Page curve — a graph that shows how much information the hole has already released and how much it still holds inside. A sharp kink in this graph marks the "Page time"—the moment when the hole turns from a vault into an open book.
In the new work, the scientists considered not a simple black hole but a charged and nearly two-dimensional one — whose space resembles a crumpled sheet of paper near the horizon. The key idea: the hole's behavior is influenced by two "soft modes"—barely noticeable collective motions. One is associated with the reshuffling of time labels at the horizon (the Schwarzschild mode), the other with oscillations of the electric phase (the U(1) mode). These modes act like two conductors who shift the radiation orchestra — one slows the tempo, the other speeds it up.
The authors averaged the energy and charge fluxes over these modes and found: the U(1) mode delays the Page time, while the Schwarzschild mode brings it closer. The net shift is the result of their confrontation. In the low-temperature regime, where quantum gravity effects are not yet dominant, this struggle becomes decisive. Thus, the evaporation of a charged hole turns out to be not a monotonic process but a delicate game of two invisible forces.
The Page time is named after physicist Don Page, who in 1993 proposed this curve as a way to resolve the dispute between Stephen Hawking and Leonard Susskind over whether information is lost in a black hole.
In Dan Simmons' novel "Hyperion," the Time Tombs are surrounded by anti-entropic fields that make time flow backward — an echo of the idea that black holes may return information.