3 papers
hep-th2025
Beyond Coleman's Instantons
Misao Sasaki, Vicharit Yingcharoenrat, Ying-li Zhang
In the absence of gravity, Coleman's theorem states that the -symmetric instanton solution, which is regular at the origin and exponentially decays at infinity, gives the low…
hep-th2025
Singular instantons with finite action
Misao Sasaki, Vicharit Yingcharoenrat, Ying-li Zhang
Recently, it was shown that in the absence of gravity there exist non--symmetric instanton solutions with finite action beyond Coleman's instantons. In this paper, focusing o…
astro-ph.CO2025
The Dual Primordial Black Hole Formation Scenario
Xinpeng Wang, Misao Sasaki, Ying-li Zhang
We report a novel mechanism where two families of primordial black holes (PBHs) may form at nearly the same comoving scales but at two different epochs. It is realized in two-stage…