149 citations · 671 across the 50 of their papers we have counts for
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PBH formation from overdensities in delayed vacuum transitions
Kiyoharu Kawana, TaeHun Kim, Philip Lu
Primordial black hole (PBH) formation from first-order phase transitions (FOPTs) combines two prevalent elements of beyond the Standard Model physics with wide-ranging consequences…
Late-Forming PBH: Beyond the CMB era
Philip Lu, Kiyoharu Kawana, Alexander Kusenko
The intermediate mass black hole range, , has long offered enticing possibilities for primordial black holes (PBH), with popula…
First-order phase transition and fate of false vacuum remnants
Kiyoharu Kawana, Philip Lu, Ke-Pan Xie
False vacuum remnants in first-order phase transitions in the early Universe can form compact objects which may constitute dark matter. Such remnants form because particles develop…
Old Phase Remnants in First Order Phase Transitions
Philip Lu, Kiyoharu Kawana, Ke-Pan Xie
First order phase transitions (FOPTs) are usually described by the nucleation and expansion of new phase bubbles in the old phase background. While the dynamics of new phase bubble…
Primordial black holes from a cosmic phase transition: The collapse of Fermi-balls
Kiyoharu Kawana, Ke-Pan Xie
We propose a novel primordial black hole (PBH) formation mechanism based on a first-order phase transition (FOPT). If a fermion species gains a huge mass in the true vacuum, the co…
QCD Axions and CMB Anisotropy
Satoshi Iso, Kiyoharu Kawana, Kengo Shimada
In this paper, we consider a possibility that the temperature anisotropy of cosmic microwave background (CMB) is dominantly generated by the primordial fluctuations of QCD-axion li…