Seminar detail: Simulations of global string networks and axion dark matter mass prediction

Date&Time	Tue Jan 28 2025 (17:00 - 18:00)
Speaker	Ken'ichi Saikawa
Affiliation	Institute for Theoretical Physics, Kanazawa University
Title	Simulations of global string networks and axion dark matter mass prediction
Abstract	The axion appears as a pseudo Nambu-Goldstone boson of the spontaneous breaking of the Peccei-Quinn (PQ) symmetry introduced to solve the strong CP problem, and is considered as an excellent candidate for the cold dark matter (CDM) of the Universe. If the PQ symmetry is broken after inflation, it is in principle possible to predict the axion mass from the calculation of the CDM abundance, and such a mass prediction can be used as a guide for future experimental searches. However, this requires a precise understanding of the radiation of axions from the network of global strings, which is still subject to serious controversy in the recent literature. In this work, we perform extensive numerical simulations of global string networks so that the extrapolation of the numerical results to realistic values of the string tension is adequately improved. We present our current understanding of systematic effects in the simulation results, and discuss their implications for the axion dark matter mass prediction.
Remarks
Slide/Video	video1