AXIVERSE AND BLACK HOLE

Abstract

String theory/M-theory general predicts that axionic fields with a broad mass spectrum extending below 10-10eV are produced after compactification to four dimensions. These axions/fields provoke a rich variety of cosmophysical phenomena on different scales depending on their masses and provide us new windows to probe the ultimate theory. In this article, after overviewing this axiverse idea1, I take up the black hole instability as the most fascinating one among such axionic phenomena and explain its physical mechanism and astrophysical predictions.