GPPU Seminar

Date

10:00-12:00, August 07th, 2017

Place

Room 205, Science Complex A (H-02) map

Abstract

A large number of independent astrophysical/cosmological observations have been demonstrating the existence of a new form of matter in the Universe, dubbed dark matter. Our knowledge of dark matter is limited, although its identity and nature have been intensively investigated. In this seminar, we review a particle physics perspective of dark matter. We see that no particle in the standard model of particle physics satisfies the known natures of dark matter such as its long lifetime, sufficiently small velocity, and so on - in other words, dark matter provides an intriguing hint of physics beyond the standard model. The longevity requires a new symmetry in physics beyond the standard model such as Z2-odd weakly interacting massive particle (WIMP), and also constrains the interaction strength of dark matter particle. Dark matter particles are produced in the early Universe in various ways depending on its interaction strength. By taking specific production mechanism, we see the resultant velocity of dark matter and its imprints on structure formation. We conclude the seminar by discussing a newly proposed possibility of a larger symmetry to ensure the longevity of dark matter, where the production mechanism can be different from that in standard WIMP scenarios.

Point

GSP 1