THE PARADOX OF AXIONS SURVIVING PRIMORDIAL MAGNETIC-FIELDS

In the presence of primordial magnetic fields the oscillating cosmic a xion field drives an oscillating electric field. The ensuing dissipati on of axions is found to be inversely proportional to the conductivity of the primordial plasma. This counterintuitive result is essentially equivalent to ''Zeno's paradox'' or the ''watched-pot effect'' of qua ntum mechanics. It implies that the standard predictions of the cosmic axion density remain unaltered even if primordial magnetic fields are strong.