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Clipping the Cosmos: The Bias and Bispectrum of Large Scale Structure
Bias Bispectrum Large Scale Structure
2011/10/21
A large fraction of the information collected by cosmological surveys is simply discarded to avoid lengthscales which are difficult to model theoretically. We introduce a new technique which enables t...
On the redundancy of operators and the bispectrum in the most general second-order scalar-tensor theory
redundancy operators bispectrum general second-order scalar-tensor theory
2011/10/19
In this short note we explain how to use the linear equation of motions to simplify the third-order action for the cosmological fluctuations. No field redefinition is needed in this exact procedure wh...
An Estimator for statistical anisotropy from the CMB bispectrum
Estimator statistical anisotropy CMB bispectrum
2011/10/13
Various data analyses of the Cosmic Microwave Background (CMB) provide observational hints of statistical isotropy breaking. Some of these features can be studied within the framework of primordial ve...
Violation of the Rotational Invariance in the CMB Bispectrum
Violation Rotational Invariance CMB Bispectrum
2011/9/27
We investigate a statistical anisotropy on the Cosmic Microwave Background (CMB) bispectrum which can be generated from the primordial non-Gaussianity induced by quantum fluctuations of a vector field...
Primordial non-Gaussianity in the Bispectrum of the Halo Density Field
Inflation Large Scale Structure Primordial non-Gaussianity
2010/11/11
The bispectrum vanishes for linear Gaussian elds and is thus a sensitive probe of non-
linearities and non-Gaussianities in the cosmic density eld. Hence, a detection of the bispectrum in the halo ...
Measurement of the cosmic microwave background (CMB) bispectrum, or three-point correlation function, has now become one of the principle efforts in early-Universe cosmology. Here we show that there i...
Oscillations in the bispectrum
Cosmology and Extragalactic Astrophysics (astro-ph.CO) General Relativity and Quantum Cosmology (gr-qc)
2010/12/29
There exist several models of inflation that produce primordial bispectra that contain a large number of oscillations. In this paper we discuss these models, and aim at finding a method of detecting s...
Impact of Instrumental Systematics on the CMB Bispectrum
Cosmology and Extragalactic Astrophysics (astro-ph.CO)
2010/12/28
We study the effects of instrumental systematics on the estimation of primordial non-Gaussianity using the cosmic microwave background (CMB) bispectrum from both the temperature and the polarization a...
The CMB Bispectrum, Trispectrum, non-Gaussianity, and the Cramer-Rao Bound
Cosmology and Extragalactic Astrophysics (astro-ph.CO)
2010/12/23
Minimum-variance estimators for the parameter fnl that quantifies local-model non-Gaussianity can be constructed from the cosmic microwave background (CMB) bispectrum (three-point function) and also f...
The Matter Bispectrum in N-body Simulations with non-Gaussian Initial Conditions
theory large-scale structure of the Universe
2010/3/9
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 wit...