Pre-Hawking radiation cannot prevent the formation of apparent horizon

Journal Article · 29 March 2018 · Physical Review D

DOI: https://doi.org/10.1103/physrevd.97.064045 · OSTI ID:1436413

Chen, Pisin ^[1]; Unruh, William G. ^[2]; Wu, Chih-Hung ^[3]; Yeom, Dong-Han ^[4]

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1. National Taiwan Univ., Taipei (Taiwan). Leung Center for Cosmology and Particle Astrophysics; National Taiwan Univ., Taipei (Taiwan). Dept. of Physics; SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology
2. Univ. of British Columbia, Vancouver, BC (Canada). Dept. of Physics and Astronomy
3. National Taiwan Univ., Taipei (Taiwan). Leung Center for Cosmology and Particle Astrophysics; National Taiwan Univ., Taipei (Taiwan). Dept. of Physics; SLAC National Accelerator Lab., Menlo Park, CA (United States)
4. National Taiwan Univ., Taipei (Taiwan). Leung Center for Cosmology and Particle Astrophysics; Asia Pacific Center for Theoretical Physics, Pohang (Republic of Korea); Postech, Pohan (Republic of Korea). Dept. of Physics

As an attempt to solve the black hole information loss paradox, recently there has been the suggestion that, due to semiclassical effects, a pre-Hawking radiation must exist during the gravitational collapse of matter, which in turn prevents the apparent horizon from forming. Assuming the pre-Hawking radiation does exist, here we argue the opposite. First we note that the stress energy tensor near the horizon for the pre-Hawking radiation is far too small to do anything to the motion of a collapsing shell. Thus the shell will always cross the apparent horizon within a finite proper time. Moreover, the amount of energy that can be radiated must be less than half of the total initial energy (if the particle starts at rest at infinity) before the shell becomes a null shell and cannot radiate any more without becoming tachyonic. Here, we conclude that for any gravitational collapsing process within Einstein gravity and semiclassical quantum field theory, the formation of the apparent horizon is inevitable. Pre-Hawking radiation is therefore not a valid solution to the information paradox.

• Research Organization: SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
• Sponsoring Organization: Ministry of Science and Technology (MOST); National Taiwan University; Natural Sciences and Engineering Research Council of Canada (NSERC); USDOE
• Grant/Contract Number: AC02-76SF00515; AC03-76SF00515
• OSTI ID: 1436413
• Journal Information: Physical Review D, Journal Name: Physical Review D Journal Issue: 6 Vol. 97; ISSN PRVDAQ; ISSN 2470-0010
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English