Primordial magnetic fields with X-ray and S-Z cluster survey
  The effect of primordial magnetic fields on X-ray or S-Z galaxy cluster
survey is investigated. After recombination, the primordial magnetic fields
generate additional density fluctuations. Such density fluctuations enhance the
number of galaxy clusters. Taking into account the density fluctuations
generated by primordial magnetic fields, we calculate the number of galaxy
clusters based on the Press-Schechter formalism. Comparing with the results of
Chandra X-ray galaxy cluster survey, we found that the existence of primordial
magnetic fields with amplitude larger than 10 nGuass would be inconsistent.
Moreover, we show that S-Z cluster surveys also have a sensitivity to constrain
primordial magnetic fields. Especially SPT S-Z cluster survey has a potential
to constrain the primordial magnetic fields with several nano Gauss.
