RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences

Dark Matter as the Z2 Partner of the Standard Model Higgs Boson

A possible gamma-ray excess from the Galactic halo favors dark matter with a mass of several hundred GeV. In previous work, we found that an electroweak scalar doublet is a particularly economical—and nearly uniquely selected—interpretation among simple renormalizable thermal dar...

Swarming by curvature control in arbitrary dimension

We consider an interacting particle system proposed in the literature to model fish behavior. In this model, the agents move at constant speed and control the curvature of their trajectory (i.e. the time-derivative of their velocity) so as to align their velocity with that of the...

Experiments on entrainment and mixing in particle-driven gravity currents

New experiments with particle-driven, finite-volume gravity currents show that some of the ambient fluid displaced up and over the head of the current becomes mixed into the current. Measurements show that this leads to an increase in volume of the current at a similar rate to th...