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oai:recercat.cat:2445/1275262025-12-05T16:10:18Zcom_2072_1057col_2072_478904col_2072_478917

urn:hdl:2445/127526 Prospects for constraining the shape of non-Gaussianity with the scale-dependent bias Noreña, Jorge Verde, Licia Barenboim, Gabriela Bosch, Cristian Cosmologia Astrofísica Cosmology Astrophysics We consider whether the non-Gaussian scale-dependent halo bias can be used not only to constrain the local form of non-Gaussianity but also to distinguish among different shapes. In particular, we ask whether it can constrain the behavior of the primordial three-point function in the squeezed limit where one of the momenta is much smaller than the other two. This is potentially interesting since the observation of a three-point function with a squeezed limit that does not go like the local nor equilateral templates would be a signal of non-trivial dynamics during inflation. To this end we use the quasi-single field inflation model of Chen & Wang [1, 2] as a representative two-parameter model, where one parameter governs the amplitude of non-Gaussianity and the other the shape. We also perform a model-independent analysis by parametrizing the scale-dependent bias as a power-law on large scales, where the power is to be constrained from observations. We find that proposed large-scale structure surveys (with characteristics similar to the dark energy task force stage IV surveys) have the potential to distinguish among the squeezed limit behavior of different bispectrum shapes for a wide range of fiducial model parameters. Thus the halo bias can help discriminate between different models of inflation. 2019-01-22T13:47:49Z 2019-01-22T13:47:49Z 2012-08 2019-01-22T13:47:50Z info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Versió postprint del document publicat a: https://doi.org/10.1088/1475-7516/2012/08/019 Journal of Cosmology and Astroparticle Physics, 2012, vol. 2012, num. 019 https://doi.org/10.1088/1475-7516/2012/08/019 info:eu-repo/grantAgreement/EC/FP7/240117/EU//PHYS.LSS (c) IOP Publishing and Sissa Medialab, 2012 info:eu-repo/semantics/openAccess Institute of Physics (IOP) Articles publicats en revistes (Institut de Ciències del Cosmos (ICCUB))