8 papers
Emergent equilibrium-like yields from nonequilibrium cascade dynamics
Takeshi Fukuyama
We study nonequilibrium cascades in which fragile bound or coherent structures are formed through intermediate states rather than by direct equilibration. Motivated by light-nuclei…
Universal Mechanism of Dynamical Memory in Light-Nuclei Formation and Cosmological Bose-Einstein Condensation
Takeshi Fukuyama
We identify a common reduced nonequilibrium structure in light-nuclei formation in heavy-ion collisions and cosmological Bose-Einstein condensation. In the heavy-ion system, elimin…
Bose-Einstein Condensate Cosmology within the Framework of QCD Axion
Takeshi Fukuyama
Bose-Einstein Condensation (BEC) cosmology is analyzed in the framework of a string-inspired axion model. The dispersion relation of the axionic mode includes both gravitational an…
Blandford-Znajek Effect and Neutrino Pair Annihilation as the Central Engines of Gamma Ray Bursts and Blazars
Takeshi Fukuyama
The central engine of gamma-ray burst is considered. Blandford-Znajek (BZ) process is reconsidered under the asymtotic magnetic condition (rotation axis) at $r…
Infrared Divergence in QED and the Fluctuation of Electromagnetic Fields
Takeshi Fukuyama
We establish a no-go result for the infrared sector of quantum electrodynamics. Using the standard Fock-space formulation, we show that gauge invariance enforces coherent soft-phot…
The self-attractive ultralight axion and its time scale of collapsing in general relativistic framework
Takeshi Fukuyama
The formation of supermassive black holes (SMBHs) at high red shift by ultralight axion dark matter (DM) is discussed in the general relativistic framework. The critical condit…
Ultralight axion and modern cosmology tensions
Takeshi Fukuyama
String-inspired axion model is considered to comprehensively solve the problems of modern cosmology, Hubble tension problem, the origin of the stochastic gravitational wave backgro…
Insights from the magnetic field dependence of the muonium-to-antimuonium transition
Takeshi Fukuyama, Yukihiro Mimura, Yuichi Uesaka
The muonium-to-antimuonium transition experiment is about to be updated. Notably, the experiment at J-PARC in Japan can explore the magnetic field dependence of the transition prob…