Kavli Affiliate: Misao Sasaki | First 5 Authors: Chul-Moon Yoo, Tomohiro Harada, Shin’ichi Hirano, Hirotada Okawa, Misao Sasaki | Summary: We numerically study the primordial black hole (PBH) formation by an isocurvature perturbation of a massless scalar field on super Hubble scales in the radiation-dominated universe. As a first step we perform simulations of spherically […]
Kavli Affiliate: Eiichiro Komatsu | First 5 Authors: Laura Herold, Elisa G. M. Ferreira, Eiichiro Komatsu, , | Summary: A dark energy-like component in the early universe, known as early dark energy (EDE), is a proposed solution to the Hubble tension. Currently, there is no consensus in the literature as to whether EDE can simultaneously […]
Kavli Affiliate: Satoshi Shirai | First 5 Authors: Masahiro Ibe, Shin Kobayashi, Yuhei Nakayama, Satoshi Shirai, | Summary: We discuss cosmological constraints on a dark scalar particle mixing with the Standard Model Higgs boson. We pay particular attention to the dark scalar production process when the reheating temperature of the Universe is very low, which […]
Kavli Affiliate: Masahiro Kawasaki | First 5 Authors: Masahiro Kawasaki, Kazuyoshi Miyazaki, Kai Murai, Hiromasa Nakatsuka, Eisuke Sonomoto | Summary: Ultra-light axion-like particle (ULAP) with mass $m sim 10^{-22} ~mathrm{eV}$ has recently been attracting attention as a possible solution to the small-scale crisis. ULAP forms quasi-stable objects called oscillons/I-balls, which can survive up to a […]
Kavli Affiliate: Masahiro Takada | First 5 Authors: Youngsoo Park, Tomomi Sunayama, Masahiro Takada, Yosuke Kobayashi, Hironao Miyatake | Summary: We present a novel analysis for cluster cosmology that fully forward models the abundances, weak lensing, and the clustering of galaxy clusters. Our analysis notably includes an empirical model for the anisotropic boosts impacting the […]
Kavli Affiliate: Shunsaku Horiuchi | First 5 Authors: Kanji Mori, Tomoya Takiwaki, Kei Kotake, Shunsaku Horiuchi, | Summary: Axion-like particles (ALPs) are a class of hypothetical pseudoscalar particles which feebly interact with ordinary matter. The hot plasma of core-collapse supernovae is a possible laboratory to explore physics beyond the standard model including ALPs. Once produced, […]
Kavli Affiliate: Toshiyuki Kobayashi | First 5 Authors: Toshiyuki Kobayashi, , , , | Summary: How does an irreducible representation of a group behave when restricted to a subgroup? This is part of branching problems, which are one of the fundamental problems in representation theory, and also interact naturally with other fields of mathematics. This […]
Kavli Affiliate: Toshiyuki Kobayashi | First 5 Authors: Toshiyuki Kobayashi, , , , | Summary: How does an irreducible representation of a group behave when restricted to a subgroup? This is part of branching problems, which are one of the fundamental problems in representation theory, and also interact naturally with other fields of mathematics. This […]
Kavli Affiliate: David N. Spergel | First 5 Authors: Pablo Villanueva-Domingo, Francisco Villaescusa-Navarro, Shy Genel, Daniel Anglés-Alcázar, Lars Hernquist | Summary: We present new constraints on the masses of the halos hosting the Milky Way and Andromeda galaxies derived using graph neural networks. Our models, trained on thousands of state-of-the-art hydrodynamic simulations of the CAMELS […]
Kavli Affiliate: Hitoshi Murayama | First 5 Authors: Ronny Frumkin, Yonit Hochberg, Eric Kuflik, Hitoshi Murayama, | Summary: We propose a new thermal dark matter candidate whose abundance is determined by the freezeout of inverse decays. The relic abundance depends parametrically only on a decay width, while matching the observed value requires that the coupling […]