# Acoustic signatures in the Cosmic Microwave Background bispectrum from primordial magnetic fields

@article{Cai2010AcousticSI, title={Acoustic signatures in the Cosmic Microwave Background bispectrum from primordial magnetic fields}, author={Rong-gen Cai and Bing Hu and Hong-bo Zhang}, journal={Journal of Cosmology and Astroparticle Physics}, year={2010}, volume={2010}, pages={025-025} }

Using the full radiation transfer function, we numerically calculate the CMB angular bispectrum seeded by the compensated magnetic scalar density mode. We find that, for the string inspired primordial magnetic fields characterized by index nB = −2.9 and mean-field amplitude Bλ = 9nG, the angular bispectrum is dominated by two primordial magnetic shapes. The first magnetic shape looks similar to the one from local-type primordial curvature perturbations, so both the amplitude and profile of the… Expand

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#### References

SHOWING 1-10 OF 128 REFERENCES

Cosmic microwave background bispectrum from primordial magnetic fields on large angular scales.

- Physics, Medicine
- Physical review letters
- 2009

This work proposes a novel probe of stochastic primordial magnetic fields that exploits the characteristic CMB non-Gaussianity that they induce, and compute the CMB bispectrum (b(l1l2l3)) induced by such fields on large angular scales. Expand

The cosmic microwave background temperature bispectrum from scalar perturbations induced by primordial magnetic fields

- Physics
- 2009

We evaluate the angular bispectrum of the CMB temperature anisotropy at large angular scale due to a stochastic background of primordial magnetic fields. The shape of non-Gaussianity depends on the… Expand

Semi-analytical approach to magnetized temperature autocorrelations

- Physics
- 2007

The cosmic microwave background (CMB) temperature autocorrelations, induced by a magnetized adiabatic mode of curvature inhomogeneities, are computed with semi-analytical methods. As suggested by the… Expand

Acoustic signatures in the primary microwave background bispectrum

- Physics
- 2001

If the primordial fluctuations are non-Gaussian, then this non-Gaussianity will be apparent in the cosmic microwave background (CMB) sky. With their sensitive all-sky observation, MAP and Planck… Expand

Can a primordial magnetic field originate large-scale anomalies in WMAP data?

- Physics
- 2008

Several accurate analyses of the cosmic microwave background (CMB) temperature maps from the Wilkinson Microwave Anisotropy Probe (WMAP) have revealed a set of anomalous results, at large angular… Expand

Cosmic microwave background bispectrum on small angular scales

- Physics
- 2008

This article investigates the nonlinear evolution of cosmological perturbations on sub-Hubble scales in order to evaluate the unavoidable deviations from Gaussianity that arise from the nonlinear… Expand

Magnetized CMB observables: a dedicated numerical approach

- Physics
- 2008

Large-scale magnetic fields affect the scalar modes of the geometry whose ultimate effect is to determine the anisotropies of the cosmic microwave background (CMB in what follows). For the first… Expand

Evolution of Cosmological Perturbations in the Presence of Primordial Magnetic Fields

- Physics
- 2009

Possible existence of the primordial magnetic fields has affected the structure formation of the universe. In this paper it is shown that the initial conditions for density perturbations with… Expand

Cosmological perturbations on a magnetized Bianchi I background

- Physics
- 2000

Motivated by the isotropy of the CMB spectrum, all existing studies of magnetized cosmological perturbations employ FRW backgrounds. However, it is important to know the limits of this approximation… Expand

Primordial bispectrum information from CMB polarization

- Physics
- 2004

After the precise observations of the cosmic microwave background (CMB) anisotropy power spectrum, attention is now being focused on higher order statistics of the CMB anisotropies. Since linear… Expand