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We present N-body simulations for generic non-Gaussian initial conditions with the aim of exploring and modelling the scale-dependent halo bias. This effect is evident at very large scales requiring large simulation boxes. In addition, the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Christian Wagner , Licia Verde

Higher-order spectra (or polyspectra), defined as the Fourier Transform of a stationary process' autocumulants, are useful in the analysis of nonlinear and non Gaussian processes. Polyspectral means are weighted averages over Fourier…

Statistics Theory · Mathematics 2024-10-23 Dhrubajyoti Ghosh , Tucker McElroy , Soumendra Lahiri

The non-Gaussianity of inflationary perturbations, as encoded in the bispectrum (or 3-point correlator), has become an important additional way of distinguishing between inflation models, going beyond the linear Gaussian perturbation…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-23 Bartjan van Tent

We propose a fast and efficient bispectrum statistic for Cosmic Microwave Background (CMB) temperature anisotropies to constrain the amplitude of the primordial non-Gaussian signal measured in terms of the non-linear coupling parameter…

Astrophysics · Physics 2009-11-11 P. Cabella , F. K. Hansen , M. Liguori , D. Marinucci , S. Matarrese , L. Moscardini , N. Vittorio

Oscillations in the primordial bispectrum are sourced by a range of inflationary phenomena, including features in the inflaton potential and interactions with massive fields through the Cosmological Collider scenario. These signatures offer…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-20 Samuel Goldstein , Oliver H. E. Philcox , Emanuele Fondi , William R. Coulton

We calculate the scale dependence of the bispectrum and trispectrum in (quasi) local models of non-Gaussian primordial density perturbations, and characterize this scale dependence in terms of new observable parameters. They can help to…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-12 Christian T. Byrnes , Mischa Gerstenlauer , Sami Nurmi , Gianmassimo Tasinato , David Wands

We introduce a novel logarithmic spectral estimation method for dark matter searches using gravitational-wave detectors, integrating established dark matter search techniques with insights from computer music analysis. By leveraging…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-06 Alexandre Göttel , Vivien Raymond

When analyzing the galaxy bispectrum measured from spectroscopic surveys, it is imperative to account for the effects of non-uniform survey geometry. Conventionally, this is done by convolving the theory model with the the window function;…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-05 Oliver H. E. Philcox

Scalar metric fluctuations generically source a spectrum of gravitational waves at second order in perturbation theory, poising gravitational wave experiments as potentially powerful probes of the small-scale curvature power spectrum. We…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-20 Peter Adshead , Kaloian D. Lozanov , Zachary J. Weiner

Future Large Scale Structure surveys are expected to improve over 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…

Dark matter evolution during the process of cosmological structure formation can be described in terms of a one-particle irreducible effective action at a characteristic scale $k_m$ and a loop expansion below this scale, based on the…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-02 Stefan Floerchinger , Mathias Garny , Aris Katsis , Nikolaos Tetradis , Urs Achim Wiedemann

We calculate the shape correlations between trispectra in various equilateral non-Gaussian models, including DBI inflation, ghost inflation and Lifshitz scalars, using the full trispectrum as well as the reduced trispectum. We find that…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-06 Keisuke Izumi , Shuntaro Mizuno , Kazuya Koyama

Recent studies have demonstrated that {\em secondary} non-Gaussianity induced by gravity will be detected with a high signal-to-noise (S/N) by future and even by on-going weak lensing surveys. One way to characterise such non-Gaussianity is…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-05 D. Munshi , T. Namikawa , T. D. Kitching , J. D. McEwen , R. Takahashi , F. R. Bouchet , A. Taruya , B. Bose

Motivated by the properties of early universe scenarios that produce observationally large local non-Gaussianity, we perform N-body simulations with non-Gaussian initial conditions from a generalized local ansatz. The bispectra are…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-18 Sarah Shandera , Neal Dalal , Dragan Huterer

The gravitational growth index formalism provides a model independent way to look for deviations from general relativity by testing dark energy physics distinct from its effects on the cosmic expansion history. Here we extend the approach…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-18 Eric V. Linder

We address the issue of setting up generic non-Gaussian initial conditions for N-body simulations. We consider inflationary-motivated primordial non-Gaussianity where the perturbations in the Bardeen potential are given by a dominant…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Christian Wagner , Licia Verde , Lotfi Boubekeur

Higher-order clustering statistics, like the galaxy bispectrum, can add complementary cosmological information to what is accessible with two-point statistics, like the power spectrum. While the standard way of measuring the bispectrum…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-14 Joyce Byun , Andrea Oddo , Cristiano Porciani , Emiliano Sefusatti

We present a general formalism that provides a systematic computation of the linear and non-linear perturbations for an arbitrary number of cosmological fluids in the early Universe going through various transitions, in particular the decay…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 David Langlois , Angela Lepidi

We present an all-sky formalism for the Cosmic Microwave Background (CMB) bispectrum induced by the primordial non-Gaussianities not only in scalar but also in vector and tensor fluctuations. We find that the bispectrum can be formed in an…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Maresuke Shiraishi , Daisuke Nitta , Shuichiro Yokoyama , Kiyotomo Ichiki , Keitaro Takahashi

Studying the primordial non-Gaussianity of inflationary perturbations is crucial for testing the inflation paradigm of the early universe. In this work, we conduct a comprehensive analysis of the angular bispectrum and trispectrum of…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-30 Jun-Peng Li , Sai Wang , Zhi-Chao Zhao , Kazunori Kohri
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