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Related papers: A Model for the Squeezed Bispectrum in the Non-Lin…

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The estimation of the covariance function of a stochastic process, or signal, is of integral importance for a multitude of signal processing applications. In this work, we derive closed-form expressions for the variance of covariance…

Signal Processing · Electrical Eng. & Systems 2021-10-05 Filip Elvander , Johan Karlsson

Context. The overdensity inside a cosmological sub-volume and the tidal fields from its surroundings affect the matter distribution of the region. The resulting difference between the local and global power spectra is characterized by the…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-11 Gábor Rácz , István Szapudi , István Csabai

Discrete-time models are very convenient to simulate a nonlinear system on a computer. In order to build the discrete-time simulation models for the nonlinear feedback systems (which is a very important class of systems in many…

Systems and Control · Computer Science 2018-05-15 Rishi Relan , Johan Schoukens

We investigate three-point statistics in weak lensing convergence, through the integrated bispectrum. This statistic involves measuring power spectra in patches, and is thus easy to measure, and avoids the complexity of estimating the very…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-13 Gabriel Jung , Toshiya Namikawa , Michele Liguori , Dipak Munshi , Alan Heavens

Deformed shell model (DSM) based on Hartree-Fock intrinsic states is applied to address two current problems of interest. Firstly, in the $f_{5/2}pg_{9/2}$ model space with jj44b effective interaction along with isospin projection, DSM is…

Nuclear Theory · Physics 2016-10-11 R. Sahu , V. K. B. Kota

We examine the effect of a threshold bias on the power spectrum and the bispectrum in an ensemble of numerical simulations (Gaussian initial perturbations with power law spectra P(k) \sim k^n, n=+1, 0, -1, -2) and compare our results with…

Astrophysics · Physics 2015-06-24 J. N. Fry , Adrian L. Melott , Sergei F. Shandarin

We present measurements of the dark matter bispectrum in N-body simulations with non-Gaussian initial conditions of the local kind for a large variety of triangular configurations and compare them with predictions from Eulerian Perturbation…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Emiliano Sefusatti , Martin Crocce , Vincent Desjacques

We analyze the spectral properties of squeezed light produced by means of pulsed, single-pass degenerate parametric down-conversion. The multimode output of this process can be decomposed into characteristic modes undergoing independent…

Quantum Physics · Physics 2007-05-23 Wojciech Wasilewski , A. I. Lvovsky , Konrad Banaszek , Czeslaw Radzewicz

The bispectrum, the three-point function of density fluctuations in Fourier space, is the lowest order statistic that carries information about the spatial coherence of large-scale structures. For Gaussian initial conditions, when the…

We present a phenomenological modification of the standard perturbation theory prediction for the bispectrum in redshift space that allows us to extend the model to mildly non-linear scales over a wide range of redshifts, $z\leq1.5$. We…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-16 Héctor Gil-Marín , Christian Wagner , Jorge Noreña , Licia Verde , Will Percival

A primary spectral submanifold (SSM) is the unique smoothest nonlinear continuation of a nonresonant spectral subspace $E$ of a dynamical system linearized at a fixed point. Passing from the full nonlinear dynamics to the flow on an…

Dynamical Systems · Mathematics 2023-06-28 George Haller , Bálint Kaszás , Aihui Liu , Joar Axås

We study theoretically the squeezing spectrum and second-order correlation function of the output light for an optomechanical system in which a mechanical oscillator modulates the cavity linewidth (dissipative coupling). We find strong…

Mesoscale and Nanoscale Physics · Physics 2015-12-14 Dainius Kilda , Andreas Nunnenkamp

Quantized descriptions of nonlinear-optical processes can be relevant from the perspective of developing novel nonclassical sources of light. As a special case, it is useful to characterize light emitted by classically driven systems, since…

Quantum Physics · Physics 2023-03-21 Ákos Gombkötő

Based on a suite of state-of-the-art high-resolution $N$-body simulations, we revisit the so-called halofit model (Smith et al. 2003) as an accurate fitting formula for the nonlinear matter power spectrum. While the halofit model has been…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Ryuichi Takahashi , Masanori Sato , Takahiro Nishimichi , Atsushi Taruya , Masamune Oguri

By a careful implementation of gauge transformations involving long-wavelength modes, we show that a variety of effects involving squeezed bispectrum configurations, for which one Fourier mode is much shorter than the other two, cannot be…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-03 Sabino Matarrese , Luigi Pilo , Rocco Rollo

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 revisit the power spectrum analysis of the complete sample of the two degree field (2dF) QSO redshift (2QZ) survey, as a complementary test of the work by Outram et al. (2003). A power spectrum consistent with that of the 2QZ group is…

Astrophysics · Physics 2009-11-10 Kazuhiro Yamamoto

We study the halo-matter cross bispectrum in the presence of primordial non-Gaussianity of the local type. We restrict ourselves to the squeezed limit, for which the calculation are straightforward, and perform the measurements in the…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-10 Azadeh Moradinezhad Dizgah , Kwan Chuen Chan , Jorge Noreña , Matteo Biagetti , Vincent Desjacques

We use a set of numerical N-body simulations to study the large-scale behavior of the reduced bispectrum of dark matter and compare the results with the second-order perturbation theory and the halo models for different halo mass functions.…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 Hong Guo , Y. P. Jing

The bispectrum is the leading non-Gaussian statistic in Large-Scale Structure (LSS) clustering and encodes the interactions in the underlying field. It is thus an important diagnostic for primordial non-Gaussianity and higher order galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-20 Theodore Steele , Tobias Baldauf