Axions are peculiar hypothetical particles that could both solve the CP problem of quantum chromodynamics and at the same time account for the dark matter of th

This book is dedicated to Lev Okun, who passed away in November 2015. He was a true pioneer in probing fundamental dynamics.The book has two objectives. First i

Much of what we know about neutrinos is revealed by astronomical observations, and the same applies to the axion, a conjectured new particle that is a favored c

An accelerating convergence of interests of particle physics and modern experimental and theoretical astrophysics has been witnessed in the past few years. One

Deciphering the script for the Big Bang has now become a joint effort of particle physicists and cosmologists. The origin and first moments of the early Univers