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Phase-space methods allow one to go beyond the mean-field approximation to simulate the quantum dynamics of interacting fields. Here, we obtain a technique for initializing either Wigner or positive-P phase-space simulations of…

Quantum Physics · Physics 2020-01-08 King Ng , Rodney Polkinghorne , Bogdan Opanchuk , Peter D. Drummond

Gaussian graphical models are widely used to infer dependence structures. Bayesian methods are appealing to quantify uncertainty associated with structural learning, i.e., the plausibility of conditional independence statements given the…

Methodology · Statistics 2025-11-05 Deborah Sulem , Jack Jewson , David Rossell

Measurements of primordial non-Gaussianity ($f_{NL}$) open a new window onto the physics of inflation. We describe a fast cubic (bispectrum) estimator of $f_{NL}$, using a combined analysis of temperature and polarization observations. The…

Astrophysics · Physics 2009-02-23 Amit P. S. Yadav , Eiichiro Komatsu , Benjamin D. Wandelt

We discuss generation of non-Gaussianity in density perturbation through the super-horizon evolution during inflation by using the so-called $\delta N$ formalism. We first provide a general formula for the non-linearity parameter generated…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Takahiro Tanaka , Teruaki Suyama , Shuichiro Yokoyama

In this contribution a broad overview of the methodologies of cosmological N-body simulations and a short introduction explaining the general idea behind such simulations is presented. After explaining how to set up the initial conditions…

Astrophysics · Physics 2009-11-10 Alexander Knebe

We derive the expressions for the 1-loop corrections in cosmological, Eulerian, perturbation theory to the matter bispectrum and to the galaxy bispectrum, assuming local galaxy bias, in presence of non-Gaussian initial conditions. We…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-29 Emiliano Sefusatti

In this paper, we propose some efficient and robust numerical methods to compute the ground states and dynamics of Fractional Schr\"{o}dinger Equation (FSE) with a rotation term and nonlocal nonlinear interactions. In particular, a newly…

Numerical Analysis · Mathematics 2016-09-21 Xavier Antoine , Qinglin Tang , Yong Zhang

The optimal selection of experimental conditions is essential to maximizing the value of data for inference and prediction, particularly in situations where experiments are time-consuming and expensive to conduct. We propose a general…

Machine Learning · Statistics 2012-12-04 Xun Huan , Youssef M. Marzouk

Bayesian models based on Gaussian processes (GPs) offer a flexible framework to predict spatially distributed variables with uncertainty. But the use of nonstationary priors, often necessary for capturing complex spatial patterns, makes…

Machine Learning · Statistics 2025-06-02 Gabriel V Cardoso , Mike Pereira

We compute non-Gaussianities in N-flation, a string motivated model of assisted inflation with quadratic, separable potentials and masses given by the Marcenko-Pastur distribution. After estimating parameters characterizing the bi- and…

High Energy Physics - Theory · Physics 2010-10-27 Diana Battefeld , Thorsten Battefeld

We describe a fast, optimal estimator for measuring angular bispectra between two correlated weakly non-Gaussian fields ($Y$ and $Z$) from observational datasets, based on a separable modal bispectrum expansion. Our methodology is…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-26 Maresuke Shiraishi , Michele Liguori , James R. Fergusson , E. P. S. Shellard

For general non-Gaussian distributions, the covariance and precision matrices do not encode the independence structure of the variables, as they do for the multivariate Gaussian. This paper builds on previous work to show that for a class…

Machine Learning · Computer Science 2025-08-18 Ujas Shah , Manuel Lladser , Rebecca Morrison

We introduce a protocol for generating a broad class of non-Gaussian (nG) quantum states via postselected weak measurement techniques. The scheme involves injecting an arbitrary quantum state and a single photon into the signal and idler…

Quantum Physics · Physics 2025-12-29 Xiao-Xi Yao , Yusuf Turek

Primordial gravitational waves could be non-Gaussian, just like primordial scalar perturbations. Although the tensor two-point function has thus-far remained elusive, the three-point function could, in principle, be large enough to be…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-14 Oliver H. E. Philcox , Maresuke Shiraishi

Universal quantum computing with continuous variables requires non-Gaussian resources, in addition to a Gaussian set of operations. A known resource enabling universal quantum computation is the cubic phase state, a non-Gaussian state whose…

A Gaussian operator basis provides a means to formulate phase-space simulations of the real- and imaginary-time evolution of quantum systems. Such simulations are guaranteed to be exact while the underlying distribution remains…

Computational Physics · Physics 2012-04-04 M. Ogren , K. V. Kheruntsyan , J. F. Corney

We present a formalism for constructing schematic diagrams to depict chaotic three-body interactions in Newtonian gravity. This is done by decomposing each interaction in to a series of discrete transformations in energy- and angular…

Solar and Stellar Astrophysics · Physics 2018-02-07 Nathan W. C. Leigh , Shalma Wegsman

Gaussian models provide an excellent effective description of many quantum many-body systems ranging from condensed matter systems all the way to neutron stars. Gaussian states are common at equilibrium when the interactions are weak.…

We classify models generating large local-type non-Gaussianity into some categories by using some "consistency relations" among the non-linearity parameters f_{NL}^{local}, \tau_{NL}^{local} and g_{NL}^{local}, which characterize the size…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-02 Teruaki Suyama , Tomo Takahashi , Masahide Yamaguchi , Shuichiro Yokoyama

In contrast to regular ordinary differential equations, the problem of accurately setting initial conditions just emerges in the context of differential-algebraic equations where the dynamic degree of freedom of the system is smaller than…

Numerical Analysis · Mathematics 2025-06-05 Michael Hanke , Roswitha März