Superconducting strings constrained by FIRAS/COBE data and large scale structure formation

Abstract

We address the question on whether superconducting cosmic strings (SCS) constrained by FIRAS/COBE results can survive as the seeds of galaxy formation. We show that SCS constrained by: (i) early FIRAS/COBE data, (ii) latest PSR 1937 + 21 timing measurements and (iii) the available anisotropy in the intensity of the cosmic microwave background ( ΔT T ) for 1° angular separation, are all compatible with the explosive scenario of galaxy formation. That is, SCS can reproduce a bubble structure with the required radius R s ⩾ (20–30) h −1 Mpc. We introduce the explicit dependence on the set of SCS evolution parameters ( α, β, γ) in the expression for R s. All these data converge to the same orders of magnitude of the SCS parameter Gμ⪅10 −6−10 −7 and of the released electromagnetic to the gravitational energy ratio f∼2×10 −2. These conclusions hold for any of the available values (α, β, γ), including latest numerical simulations. The uncertainties at present, to rule our or to accept cosmological scenarios based on SCS are discussed.