Imprints of primordial non-Gaussianity on the number counts of cosmic shear peaks
We studied the effect of primordial non-Gaussianity with varied bispectrum shapes on the number counts of signal-to-noise ratio peaks in wide-field cosmic shear maps. The two cosmological contributions to this particular weak lensing statistic, namely the chance projection of Large Scale Structure (...
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| Main Authors: | , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
20 September 2011
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| In: |
Monthly notices of the Royal Astronomical Society
Year: 2011, Volume: 416, Issue: 4, Pages: 2527-2538 |
| ISSN: | 1365-2966 |
| DOI: | 10.1111/j.1365-2966.2011.18958.x |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1111/j.1365-2966.2011.18958.x
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| Author Notes: | M. Maturi, C. Fedeli and L. Moscardini |
| Summary: | We studied the effect of primordial non-Gaussianity with varied bispectrum shapes on the number counts of signal-to-noise ratio peaks in wide-field cosmic shear maps. The two cosmological contributions to this particular weak lensing statistic, namely the chance projection of Large Scale Structure (LSS) and the occurrence of real, cluster-sized dark matter haloes, have been modelled semianalytically, thus allowing to easily introduce the effect of non-Gaussian initial conditions. We performed a Fisher matrix analysis by taking into account the full covariance of the peak counts in order to forecast the joint constraints on the level of primordial non-Gaussianity and the amplitude of the matter power spectrum that are expected from future wide-field imaging surveys. We find that positive-skewed non-Gaussianity increases the number counts of cosmic shear peaks, more so at high signal-to-noise ratio values, where the signal is mostly dominated by massive clusters as expected. The increment is at the level of ∼1 per cent for fNL= 10 and ∼10 per cent for fNL= 100 for a local shape of the primordial bispectrum, while different bispectrum shapes give generically a smaller effect. For a future survey on the model of the proposed ESA space mission Euclid and by avoiding the strong assumption of being capable of distinguishing the weak-lensing signal of galaxy clusters from the chance projection of LSSs, we forecast a 1σ error on the level of non-Gaussianity of ∼30-40 for the local and equilateral models, and of ∼100-200 for the less explored enfolded and orthogonal bispectrum shapes. |
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| Item Description: | Gesehen am 12.08.2022 |
| Physical Description: | Online Resource |
| ISSN: | 1365-2966 |
| DOI: | 10.1111/j.1365-2966.2011.18958.x |