Kavli Affiliate: Yuji Tachikawa | Summary:We study wavepackets of exotic excitations after two-dimensional fermions are scattered by the boundary condition constructed by Maldacena and Ludwig, which turns elementary excitations into exotic fractionally-charged objects. They are of interest in the s-wave approximation of the fermion-monopole scattering in four-dimensional QED and of the multi-channel Kondo effect. We […]

Kavli Affiliate: Khee-Gan Lee | Summary:Precise halo mass ($M_h$) measurements are crucial for cosmology and galaxy formation. HaloFlow introduced a simulation-based inference (SBI) framework that uses state-of-the-art simulated galaxy images to precisely infer $M_h$. However, for HaloFlow to be applied to observations, it must be generalizable even when the underlying galaxy formation physics differ from […]

Kavli Affiliate: John Silverman | Summary:The origin of the mass scaling relation between supermassive black holes (SMBHs, $M_rm BH$) and galaxies ($M_*$) remains a key open question. Rather than invoking AGN feedback, a non-causal mechanism has been proposed in which multiple mergers average out the $M_rm BH/M_*$ ratio, thus decreasing its scatter ($σ$) and forming […]

Kavli Affiliate: John Silverman | Summary:The origin of the mass scaling relation between supermassive black holes (SMBHs, $M_rm BH$) and galaxies ($M_*$) remains a key open question. Rather than invoking AGN feedback, a non-causal mechanism has been proposed in which multiple mergers average out the $M_rm BH/M_*$ ratio, thus decreasing its scatter ($σ$) and forming […]

Kavli Affiliate: John Silverman | Summary:The origin of the mass scaling relation between supermassive black holes (SMBHs, $M_rm BH$) and galaxies ($M_*$) remains a key open question. Rather than invoking AGN feedback, a non-causal mechanism has been proposed in which multiple mergers average out the $M_rm BH/M_*$ ratio, thus decreasing its scatter ($σ$) and forming […]

Kavli Affiliate: Shunsaku Horiuchi | Summary:Outflows of rapidly rotating protomagnetars have been considered as attractive sites for the synthesis of nuclei heavier than iron, but the question remains whether these nuclei are able to survive against photodisintegration as they make their way out of their formation environments. In this work, we present new analytic fitting […]

Kavli Affiliate: Toshiya Namikawa | Summary:Axions and other very weakly interacting slim particles (WISPs), with masses below 1 GeV, arise naturally in many extensions of the Standard Model of particle physics. In particular, they could offer a new framework to explain the nature of dark matter and may help address a range of puzzling observations […]

Kavli Affiliate: John Silverman | Summary:Gaseous halos around galaxies play an important role in galaxy evolution. The exchange of metals from the interstellar medium (ISM) to the circumgalactic medium (CGM) are caused by the formation, feedback, and/or merging history of galaxies. We study the variation in chemical composition between the ISM ($lesssim3,$kpc) and CGM ($sim5-10,$kpc) […]

Kavli Affiliate: Hitoshi Murayama | Summary:In this document we update the status of U.S. community inputs for the European Strategy for Particle Physics Update (ESPPU) since April 1, 2025, and offer responses to the revised questions. Major new inputs include a long-term strategy report from the National Academies of Sciences, Engineering, and Medicine and the […]

Kavli Affiliate: Yasunori Nomura | Summary:Recent developments in gravitational path integrals indicate that the nonperturbative physical Hilbert space of a closed universe is one-dimensional within each superselection sector. This raises a basic puzzle: how can a unique quantum-gravity state give rise to semiclassical physics, measurement outcomes, and classical probabilities? In this paper, we develop a […]