2025-10-22 マックス・プランク研究所
The cosmic microwave background is a snapshot of the oldest light in the cosmos. It was imprinted on the sky when the universe was just 380,000 years old. The image is based on data from the Planck mission. The data may contain information that points to energy bursts shortly after the Big Bang, so called hot spots.
© ESA/Planck Collaboration
＜関連情報＞
- https://www.mpg.de/25582443/how-can-we-observe-the-birth-of-the-universe
- https://iopscience.iop.org/article/10.3847/1538-4357/ae01a4
- https://journals.aps.org/prd/abstract/10.1103/897z-1k7m
初期宇宙からのバーストの信号 Signals of Bursts from the Very Early Universe
Leo Stodolsky and Joseph Silk
The Astrophysical Journal Published 2025 October 15
DOI:10.3847/1538-4357/ae01a4
Abstract
We consider possible observable signals from explosive events in the very early Universe, dubbed “bursts.” These could be expected in connection with massive black hole or “baby Universe” formation. We anticipate that such major disruptions of spacetime would be associated with neutrino and perhaps other pulses. While these seem to be not detectable directly, we discuss how they could lead to potentially observable signals. We analyze how the pulses from very early times may “escape,” that is, propagate to the last scattering epoch at the time tcmb and later, or alternatively be absorbed earlier, i.e., “contained.” The possibly detectable signals include effects on small regions of the cosmic microwave background, a soft X-ray resulting from positron production, or a nonthermal addition to the relic neutrino background.
宇宙初期からの陽電子信号 Positron signal from the early Univere
Leo Stodolsky,Joseph Silk
Physical Review D Published: 27 June, 2025
DOI: https://doi.org/10.1103/897z-1k7m
Abstract
Bursts from the very early Universe may lead to a detectable signal via the production of positrons, whose annihilation gives an observable x-ray signal. Using the absorption parameters for the annihilation photons of 511 keV, it is found that observable photons would originate at a redshift around ≈200–300, resulting in soft x-rays of energy ∼2–3 keV at present. Positrons are expected to be absent at these times or redshifts in the standard picture of the early universe. Detection of the x-rays would thus provide dramatic support for the hypothesis of the bursts, explosive events at very early times. We urge the search for such a signal.
