Constraints on multifield inflation from the BOSS galaxy survey

Cabass, Giovanni; Ivanov, Mikhail M.; Philcox, Oliver H. E.; Simonović, Marko; Zaldarriaga, Matías

doi:10.1103/physrevd.106.043506

“…Constraints on PNG from measurements of the LSS promise, in principle, to far surpass existing constraints (Meerburg et al 2017;Slosar et al 2019). However, to date, the important measurements of PNG from LSS (Slosar et al 2008;Ross et al 2013;Giannantonio et al 2014;Leistedt et al 2014;Ho et al 2015;Castorina et al 2019;Mueller et al 2021;Cabass et al 2022aCabass et al , 2022bD'Amico et al 2022) have not reached the level of the CMB. This is due to complexities of large-scale foregrounds (Pullen & Hirata 2013;Rezaie et al 2021), understanding the optimal statistics to use, and the challenge of modeling the LSS.…”

Section: Introductionmentioning

confidence: 99%

Quijote-PNG: Simulations of Primordial Non-Gaussianity and the Information Content of the Matter Field Power Spectrum and Bispectrum

Coulton

¹

,

Villaescusa-Navarro

²

,

Jamieson

³

et al. 2023

ApJ

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Primordial non-Gaussianity (PNG) is one of the most powerful probes of the early universe, and measurements of the large-scale structure of the universe have the potential to transform our understanding of this area. However, relating measurements of the late-time universe to the primordial perturbations is challenging due to the nonlinear processes that govern the evolution of the universe. To help address this issue, we release a large suite of N-body simulations containing four types of PNG: quijote-png. These simulations were designed to augment the quijote suite of simulations that explored the impact of various cosmological parameters on large-scale structure observables. Using these simulations, we investigate how much information on PNG can be extracted by extending power spectrum and bispectrum measurements beyond the perturbative regime at z = 0.0. This is the first joint analysis of the PNG and cosmological information content accessible with power spectrum and bispectrum measurements of the nonlinear scales. We find that the constraining power improves significantly up to k max ≈ 0.3 h Mpc − 1 , with diminishing returns beyond as the statistical probes signal-to-noise ratios saturate. This saturation emphasizes the importance of accurately modeling all the contributions to the covariance matrix. Further, we find that combining the two probes is a powerful method of breaking the degeneracies with the ΛCDM parameters.

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“…To tackle this issue, significant efforts have been devoted to obtain theoretical predictions of the galaxy bispectrum, via a suitable perturbative treatment valid on the largest scales (for the current state of the art, see Ivanov et al 2022, and references therein). This approach has even recently led to the first constraints on PNG using both the galaxy power spectrum and bispectrum, by analyzing data from the BOSS survey (Dawson et al 2013;Cabass et al 2022aCabass et al , 2022bD'Amico et al 2022). 13 Recent works based on field-level inference (Baumann & Green 2021;Andrews et al 2022), neural networks (Giri et al 2022), or reconstruction methods (Shirasaki et al 2021), have however shown that much more information should be present in the data.…”

Section: Introductionmentioning

confidence: 99%

“…Such feature has a power law behaviour, with degree determined by the squeezed limit of the PNG bispectrum shape under study: it is most prominent for local NG, with a ∼ 1/k 2 behaviour and absent in the equilateral case. Scale-dependent bias has been the object of significant study in the literature, see, e.g., Dalal et al (2008); Matarrese & Verde (2008); Slosar et al (2008); Afshordi & Tolley (2008); Seljak (2009); Desjacques & Seljak (2010); Castorina et al (2018); Chan et al (2019); Giri et al (2022), and was used to extract local PNG constraints from BOSS data Slosar et al (2008); Ross et al (2013); Leistedt et al (2014); Mueller et al (2021); Cabass et al (2022a);D'Amico et al (2022). Recently, it has been however pointed out that accurate modeling of scale-dependent bias from PNG also depends on details of galaxy formation, making its use as a tool to measure the PNG amplitude f NL significantly more challenging than previously thought Barreira (2020Barreira ( , 2022a.…”

Section: Introductionmentioning

confidence: 99%

Quijote-PNG: Quasi-maximum Likelihood Estimation of Primordial Non-Gaussianity in the Nonlinear Dark Matter Density Field

Jung

¹

,

Karagiannis

²

,

Baldi

³

et al. 2022

ApJ

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Future large-scale structure surveys are expected to improve current bounds on primordial non-Gaussianity (PNG), with a significant impact on our understanding of early universe physics. The level of such improvements will however strongly depend on the extent to which late-time nonlinearities erase the PNG signal on small scales. In this work, we show how much primordial information remains in the bispectrum of the nonlinear dark matter density field by implementing a new, simulation-based methodology for joint estimation of PNG amplitudes (f NL) and standard Lambda cold dark matter parameters. The estimator is based on optimally compressed statistics, which, for a given input density field, combine power spectrum and modal bispectrum measurements, and numerically evaluate their covariance and their response to changes in cosmological parameters. In this first analysis, we focus on the matter density field, and we train and validate the estimator using a large suite of N-body simulations (Quijote-png), including different types of PNG (local, equilateral, orthogonal). We explicitly test the estimator’s unbiasedness, optimality, and stability with respect to changes in the total number of input realizations. While the dark matter power spectrum itself contains negligible PNG information, as expected, including it as an ancillary statistic increases the PNG information content extracted from the bispectrum by a factor of order 2. As a result, we prove the capability of our approach to optimally extract PNG information on nonlinear scales beyond the perturbative regime, up to k max = 0.5 h Mpc − 1 . At the same time, we discuss the significant information on cosmological parameters contained on these scales.

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“…the predictions for (10) where the second definition is explicitly symmetrized. Before doing so, we emphasize that we follow the recent inflationary analyses of BOSS data [16][17][18] and consider only scale-invariant templates for primordial non-Gaussianities.…”

Section: B Trispectrum Templatesmentioning

confidence: 99%

“…function. Since the early 2000s, various attempts have been made to constrain such models using both the CMB, and, more recently, spectroscopic surveys, usually by measuring a set of characteristic non-Gaussian amplitudes, f NL , which can be related to couplings in the EFTI [e.g., [13][14][15][16][17][18][19][20][21]. Whilst no detections have been yet made, bounds will continue to tighten with upcoming experiments such as the Simons Observatory [22] and the Dark Energy Spectroscopic Instrument (DESI) [23], and there is some hope of probing interesting regimes such as the f NL ≈ 1 limit in the future (which is a natural boundary for many models of multi-field inflation).…”

Section: Introductionmentioning

confidence: 99%

Colliding Ghosts: Constraining Inflation with the Parity-Odd Galaxy Four-Point Function

Cabass¹,

Ivanov²,

Philcox³

2022

Preprint

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Could new physics break the mirror symmetry of the Universe? Utilizing recent measurements of the parity-odd four-point correlation function of BOSS galaxies, we probe the physics of inflation by placing constraints on the amplitude of a number of parity-violating models. Within canonical models of (single-field, slow-roll) inflation, no parity-asymmetry can occur; however, it has recently been shown that breaking of the standard assumptions can lead to parity violation within the Effective Field Theory of Inflation (EFTI). In particular, we consider the Ghost Condensate and Cosmological Collider scenarios -the former for the leading and subleading operators in the EFTI and the latter for different values of mass and speed of an exchanged spin-1 particle -for a total of 18 models. Each instance yields a definite prediction for the inflationary trispectrum, which we convert to a late-time galaxy correlator prediction (through a highly non-trivial calculation) and constrain using the observed data. We find no evidence for inflationary parity-violation (with each of the 18 models having significances below 2.4σ), and place the first constraints on the relevant coupling strengths, at a level comparable with the theoretical perturbativity bounds. This is also the first time Cosmological Collider signatures have directly been searched for in observational data. We further show that possible secondary parity-violating signatures in galaxy clustering can be systematically described within the Effective Field Theory of Large-Scale Structure. We argue that these late-time contributions are subdominant compared to the primordial parity-odd signal for a vast region of parameter space. In summary, the results of this paper disfavor the notion that the recent hints of parity-violation observed in the galaxy sample are due to new physics.

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Constraints on multifield inflation from the BOSS galaxy survey

Cited by 68 publications

References 124 publications

Quijote-PNG: Simulations of Primordial Non-Gaussianity and the Information Content of the Matter Field Power Spectrum and Bispectrum

Quijote-PNG: Simulations of Primordial Non-Gaussianity and the Information Content of the Matter Field Power Spectrum and Bispectrum

Quijote-PNG: Quasi-maximum Likelihood Estimation of Primordial Non-Gaussianity in the Nonlinear Dark Matter Density Field

Colliding Ghosts: Constraining Inflation with the Parity-Odd Galaxy Four-Point Function

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