Kavli Affiliate: Young-kee Kim | Summary:DAMSA (DArk Messenger Searches at an Accelerator) is a novel short-baseline accelerator/beam dump experiment aimed at probing short-lived physics processes, including searches for evidence of a dark sector of particle physics and well-motivated rare Standard Model signals. Motivated by open questions in neutrino physics and the absence of conclusive evidence […]

Kavli Affiliate: Khee-Gan Lee | Summary:In this paper, we introduce MujicΛ (Mapping the Universe with Jax-based Initial Condition ReconstrΛction), an optimization-based framework for reconstructing initial conditions from realistic galaxy spectroscopic redshift surveys. Unlike standard optimization-based approaches, MujicΛ augments the L-BFGS algorithm with a projection operator and rank-order matching to enforce Gaussianity of the initial conditions […]

Kavli Affiliate: Toshiyuki Kobayashi | Summary:This expository paper explains, in the case of $mathfraksl_2$, the ideas introduced in the preprints (arXiv:2509.17007, 2604.22262), which develop a new framework for the study of multiplicities in branching laws of representations, with particular emphasis on their dependence on representation parameters. Taking the Lie algebra $mathfraksl_2$ as a guiding example, […]

Kavli Affiliate: Toshiyuki Kobayashi | Summary:We propose a structural framework for branching multiplicities in representation theory, emphasizing their behavior under variation of infinitesimal characters. For the orthogonal reductive pairs $(G,G’)$ with complexified Lie algebras $(mathfrako(n+1,mathbbC), mathfrako(n,mathbbC))$, we show that branching multiplicities are governed by universal systems of linear inequalities on the parameter space of reduced […]

Kavli Affiliate: Misao Sasaki | Summary:Fermion condensate inflation, where inflation emerges from four-fermion interactions induced by spacetime torsion, removes the need for additional scalar fields beyond the Standard Model. In this framework, the fermion field can be decomposed into two distinguished sectors, each giving rise to bound states. After integrating out fermions, the bound fields […]

Kavli Affiliate: Masahiro Kawasaki | Summary:Primordial black holes (PBHs) may form an initially clustered population depending on their production mechanism. Motivated by binary black-hole merger events observed by gravitational-wave interferometers, we revisit the evaluation of the merger rate of PBH binaries and extend the formalism to include the effects of clustering. We show that, in […]

Kavli Affiliate: David Spergel | Summary:The mean pairwise velocity of massive halos reflects the gravitational force law on cosmic scales. We combine cosmic microwave background intensity maps from the Atacama Cosmology Telescope and a galaxy catalog from the Sloan Digital Sky Survey to estimate the mean pairwise velocity using the kinematic Sunyaev-Zeldovich (kSZ) effect. On […]