Tootfinder

Dark-to-black super accretion as a mechanism for early supermassive black hole growth
Nicolas Sanchis-Gual, Juan Barranco, Juan Carlos Degollado, Dar\'io Nu\~nez
https://arxiv.org/abs/2510.00644

Dark-to-black super accretion as a mechanism for early supermassive black hole growth
The discovery of supermassive black holes with masses $\gtrsim 10^9 M_\odot$ at redshifts $z\gtrsim 10$ challenges conventional formation scenarios based on baryonic accretion and mergers within the first few hundred million years. We propose an alternative channel in which ultralight scalar dark matter undergoes dark-to-black conversion via quasi-bound state depletion around black hole seeds. We estimate the accretion rate of the scalar field as a function of the boson mass parameter $μ$ and …

Time-resolved solvation of alkali ions in superfluid helium nanodroplets: Theoretical simulation of a pump-probe study
Ernesto Garc\'ia-Alfonso, Manuel Barranco, Mart\'i Pi, Nadine Halberstadt
https://arxiv.org/abs/2507.14674

Time-resolved solvation of alkali ions in superfluid helium nanodroplets: Theoretical simulation of a pump-probe study
The solvation process of an alkali ion (Na$^+$, K$^+$, Rb$^+$, Cs$^+$) inside a superfluid $^4$He$_{2000}$ nanodroplet is investigated theoretically using liquid $^4$He time-dependent density functional theory at zero temperature. We simulate both steps of the pump-probe experiment conducted on Na$^+$ [Albrechtsen et al., Nature 623, 319 (2023)], where the alkali atom residing at the droplet surface is ionized by the pump pulse and its solvation is probed by ionizing a central xenon atom and de…