A new study suggests that Hawking radiation from black holes might cease much earlier than predicted by conventional theory. This phenomenon, occurring around the scrambling time ($u_{\text{scr}} \equiv 2a \log(a/\ell)$), is attributed to the exponential suppression of trans-Planckian interactions, a characteristic inherent in string field theories (SFT). This finding suggests that black holes could leave macroscopic remnants, offering a possible solution to the information paradox.

The researchers modified the interaction of a massless scalar field with a dynamical black hole background using a smearing operator ($e^{\ell^2\Box}$), where $\ell$ denotes the string length scale. Using this approach, they calculated the time-dependent number expectation value of outgoing Hawking particles, $\langle \hat{N}(u) \rangle$, at retarded time $u$. They observed that, while the standard Planck spectrum at the Hawking temperature is reproduced at early times ($u \ll u_{\text{scr}}$), the particle number approaches zero shortly after the scrambling time.

This early shutdown of radiation is due to the collapsing shell becoming effectively invisible to trans-Planckian modes. The main implication is the existence of macroscopic black hole remnants, which could resolve the information paradox without resorting to the complete destruction of quantum information. This model offers an alternative perspective to current debates on the fate of information in black holes and the nature of their evaporation.