Role of evaporation in gravitational collapse

Valentina Baccetti, Robert B. Mann, Daniel R. Terno*

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    24 Citations (Scopus)


    We investigate the consequences of the collapse-induced radiation anticipated before formation of the event horizon. After reviewing the principles underlying semi-classical analysis of black holes we illustrate them by modelling collapse of evaporating massive thin dust shells using two families of metrics for the exterior geometry: the outgoing Vaidya metric and the retarded Schwarzschild metric. We describe how hypothetical pre-Hawking radiation modifies the equation of motion for the shell. Provided that a non-zero radiation flux is perceived by a distant observer, the shell never gets closer than a certain sub-Planckian distance from the Schwarzschild radius. This distance depends only on the shell's mass and evaporation rate. The stress-energy tensor is everywhere finite, but a comoving observer encounters firewall-like energy density and flux. We emphasize the logical connections between different assumptions within the semi-classical approach and discuss consequences of the apparent contradictions between them.

    Original languageEnglish
    Article number185005
    Pages (from-to)1-25
    Number of pages25
    JournalClassical and Quantum Gravity
    Issue number18
    Publication statusPublished - 17 Aug 2018


    • thin shells
    • pre-Hawking radiation
    • collapse


    Dive into the research topics of 'Role of evaporation in gravitational collapse'. Together they form a unique fingerprint.

    Cite this