Amaterasu particle and the puzzles of ultra-high energy cosmic rays

• Hang Bae Kim (Hanyang University)

Ultra-high cosmic rays are the most energetic particles incident on Earth from outer space. It is one of the mysteries of science where and how these particles are produced. In this talk, I'll review the basics, the latest observations and the current issues of ultra-high cosmic rays.

Anthropic Principle

• Chanju Kim (Ehwa Womans University)

I will review the anthropic principle in science at a very basic level on the occasion of Dr. Sanghyeon Chang's retirement.

Landau-Zener production of heavy sterile neutrino dark matter

• Eung Jin Chun (KIAS)

We suggest a production mechanism of sterile neutrino dark matter whose interaction with a thermal bath is feebler than required by the freeze-in mechanism. It relies on the non-adiabatic transition in the process of the resonant conversion of thermal particles to the dark matter state, which can occur at a temperature much higher than the dark matter mass. This can be accomplished for a wide range of the sterile neutrino masses, from keV to TeV, with a judicious choice of their self-interacting couplings