相关论文: Primordial non-Gaussianity systematics from redshi…
The statistical properties of the primordial perturbations contain clues about the origins of those fluctuations. Although the Planck collaboration has recently obtained tight constraints on primordial non-gaussianity from cosmic microwave…
Discrepancies between cosmological parameter estimates from cosmic shear surveys and from recent Planck cosmic microwave background measurements challenge the ability of the highly successful $\Lambda$CDM model to describe the nature of the…
Local-type primordial non-gaussianity generates a distinctive term in the clustering of tracers of large-scale structure, behaving as $k^{-2}$ at small wavenumbers $k$. In order to use this signal in a sample of galaxies to measure the…
Non-Gaussianity in the distribution of inflationary perturbations, measurable in statistics of the cosmic microwave background (CMB) and large scale structure fluctuations, can be used to probe non-trivial initial quantum states for these…
Massive spinning particles, if present during inflation, lead to a distinctive bispectrum of primordial perturbations, the shape and amplitude of which depend on the masses and spins of the extra particles. This signal, in turn, leaves an…
We study the impact that uncertainties on assumed relations between galaxy bias parameters have on constraints of the local PNG $f_{\rm NL}$ parameter. We focus on the relation between the linear density galaxy bias $b_1$ and local PNG bias…
With the advent of large scale galaxy surveys, constraints on primordial non-Gaussianity (PNG) are expected to reach ${\cal O}(f_\text{NL}) \sim 1$. In order to fully exploit the potential of these future surveys, a deep theoretical…
Primordial non-Gaussianity is one of the most powerful probes of the inflationary epoch. The particle spectrum relevant to inflation, including masses and spins, is encoded in the precise form of statistical correlations of the adiabatic…
Primordial non-Gaussianity arising from inflationary models is a unique probe of non-trivial dynamics of the inflaton field and its interactions with other fields. Often when examining and constraining the scalar non-Gaussianity arising…
We use cosmological N-body simulations to investigate whether measurements of the moments of large-scale structure can yield constraints on primordial non-Gaussianity. We measure the variance, skewness, and kurtosis of the evolved density…
Primordial non-Gaussianity (PNG) is a common prediction of a wide class of inflationary models. Equilateral-type PNG, generically predicted by single-field inflationary models with higher-derivative interactions, imprints subtle but…
We present forecasts for constraints on deviations from Gaussian distribution of primordial density perturbations from future X-ray surveys of galaxy clusters. Our analysis is based on computing the Fisher-Matrix for number counts and…
Galaxy clusters are a valuable source of cosmological information. Their formation and evolution depends on the underlying cosmology and on the statistical nature of the primordial density fluctuations. In this work we investigate the…
We present a novel approach to analyzing astronomical spectral survey data using our non-linear extension of an online dictionary learning algorithm. Current and upcoming surveys such as SPHEREx will use spectral data to build a 3D map of…
Constraining primordial non-Gaussianities (PNG) is one of the main goals of new-generation large-scale galaxy surveys. It had been proposed that unclustered tracers (with bias $b_1=0$) could be optimal for PNG studies, and that these could…
We present photometric redshift estimates for galaxies used in the weak lensing analysis of the Dark Energy Survey Science Verification (DES SV) data. Four model- or machine learning-based photometric redshift methods -- ANNZ2, BPZ…
Future galaxy surveys promise to probe local primordial non-Gaussianity at unprecedented precision, $\sigma(f_{\rm NL}) \lesssim 1$. We study the implications for multifield inflation by considering spectator models, where inflation is…
The large-scale clustering of galaxies can serve as a probe of primordial non-Gaussianity in the Universe competitive with the anisotropies of the CMB. Here, we present improved theoretical predictions which include an important, previously…
Dusty, star forming galaxies contribute to a bright, currently unresolved cosmic far-infrared background. Deep Herschel-SPIRE images designed to detect and characterize the galaxies that comprise this background are highly confused, such…
Is there new physics hidden in the four-point function of the cosmic microwave background (CMB)? We conduct a detailed analysis of the Planck PR4 temperature and polarization trispectrum for $\ell\in[2,2048]$. Using the theoretical and…