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The algorithm ZTRACE of Monaco & Efstathiou (1999) is applied to the IRAS PSCz catalogue to reconstruct the initial conditions of our local Universe with a resolution down to ~5 Mpc/h. The 1-point PDF of the reconstructed initial conditions…

We forecast constraints on primordial non-Gaussianity (PNG) and bias parameters from measurements of galaxy power spectrum and bispectrum in future radio continuum and optical surveys. In the galaxy bispectrum, we consider a comprehensive…

宇宙学与河外天体物理 · 物理学 2018-05-04 Dionysios Karagiannis , Andrei Lazanu , Michele Liguori , Alvise Raccanelli , Nicola Bartolo , Licia Verde

We extend the formalism of time-sliced perturbation theory (TSPT) for cosmological large-scale structure to include non-Gaussian initial conditions. We show that in such a case the TSPT interaction vertices acquire new contributions whose…

宇宙学与河外天体物理 · 物理学 2019-09-20 Anagha Vasudevan , Mikhail M. Ivanov , Sergey Sibiryakov , Julien Lesgourgues

We study an ensemble of random matrices (the Rosenzweig-Porter model) which, in contrast to the standard Gaussian ensemble, is not invariant under changes of basis. We show that a rather complete understanding of its level correlations can…

介观与纳米尺度物理 · 物理学 2009-10-30 Alexander Altland , Martin Janssen , Boris Shapiro

Very high energy physics needs a coherent description of the four fundamental forces. Non-commutative geometry is a promising mathematical framework which already allowed to unify the general relativity and the standard model, at the…

数学物理 · 物理学 2009-12-07 Fabien Vignes-Tourneret

The Ginzburg-Landau phase transition model is considered in d=4-epsilon dimensions within the renormalization group (RG) approach. The problem of existence of the non-Gaussian fixed point is discussed. An equation is derived from the first…

统计力学 · 物理学 2007-05-23 J. Kaupuzs

In this paper, we revisit the recurrent back-propagation (RBP) algorithm, discuss the conditions under which it applies as well as how to satisfy them in deep neural networks. We show that RBP can be unstable and propose two variants based…

机器学习 · 计算机科学 2019-11-07 Renjie Liao , Yuwen Xiong , Ethan Fetaya , Lisa Zhang , KiJung Yoon , Xaq Pitkow , Raquel Urtasun , Richard Zemel

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…

宇宙学与河外天体物理 · 物理学 2015-05-18 Emiliano Sefusatti , Martin Crocce , Vincent Desjacques

Many-body perturbation theory (MBPT) based on Green's functions and Feynman diagrams provides a fundamental theoretical framework for various \emph{ab initio} computational approaches in molecular and materials science, including the random…

量子物理 · 物理学 2025-03-20 Yuqi Wang , Wei-Hai Fang , Zhendong Li

We investigate the non-Gaussianity of primordial curvature perturbation in the modulated reheating scenario where the primordial perturbation is generated due to the spacial fluctuation of the inflaton decay rate to radiation. We use the…

天体物理学 · 物理学 2008-11-26 Teruaki Suyama , Masahide Yamaguchi

Galaxy bispectrum is a promising probe of inflationary physics in the early universe as a measure of primordial non-Gaussianity (PNG), whereas its signal-to-noise ratio is significantly affected by the mode coupling due to non-linear…

宇宙学与河外天体物理 · 物理学 2021-01-13 Masato Shirasaki , Naonori S. Sugiyama , Ryuichi Takahashi , Francisco-Shu Kitaura

In [1], a most general higher curvature non-local gravity action was derived that admits a particular $R^2$-like inflationary solution predicting the spectral index of primordial scalar perturbations $n_s(N)\approx 1-\frac{2}{N}$, where $N$…

高能物理 - 理论 · 物理学 2023-07-18 Alexey S. Koshelev , K. Sravan Kumar , Alexei A. Starobinsky

In the last three decades, Numerical Stochastic Perturbation Theory (NSPT) has proven to be an excellent tool for calculating perturbative expansions in theories such as Lattice QCD, for which standard, diagrammatic perturbation theory is…

高能物理 - 格点 · 物理学 2025-02-05 P. Baglioni , F. Di Renzo

We explore the initial conditions for cosmological N-body simulations suitable for calculating the skewness and kurtosis of the density field. In general, the initial conditions based on the perturbation theory (PT) provide incorrect…

天体物理学 · 物理学 2009-06-23 Takayuki Tatekawa , Shuntaro Mizuno

We examine the efficiency of Recurrent Neural Networks in forecasting the spatiotemporal dynamics of high dimensional and reduced order complex systems using Reservoir Computing (RC) and Backpropagation through time (BPTT) for gated network…

信号处理 · 电气工程与系统科学 2020-02-19 Pantelis R. Vlachas , Jaideep Pathak , Brian R. Hunt , Themistoklis P. Sapsis , Michelle Girvan , Edward Ott , Petros Koumoutsakos

The modified perturbation theory (MPT), based on direct expansion of probabilities instead of amplitudes, allows one to avoid divergences in the phase-space integrals resulting from production and decay of unstable particles. In the present…

高能物理 - 唯象学 · 物理学 2009-11-07 M. L. Nekrasov

We consider the mean first passage time (MFPT) for a diffusive particle in a potential landscape with the extra condition that the particle is reset to its original position with some rate r. We study non-smooth and non-convex potentials…

统计力学 · 物理学 2025-09-16 Johannes Aspman , Daniel Mastropietro , Jakub Marecek

We investigate the Wavelet Scattering Transform (WST) as a tool for the study of Primordial non-Gaussianity (PNG) in Large Scale Structure (LSS), and compare its performance with that achievable via a joint analysis with power spectrum and…

宇宙学与河外天体物理 · 物理学 2024-03-27 Matteo Peron , Gabriel Jung , Michele Liguori , Massimo Pietroni

We consider the polynuclear growth (PNG) model in 1+1 dimension with flat initial condition and no extra constraints. Through the Robinson-Schensted-Knuth (RSK) construction, one obtains the multilayer PNG model, which consists of a stack…

数学物理 · 物理学 2007-05-23 Patrik L. Ferrari

For gradient flows, the existing structure-preserving schemes are difficult to achieve arbitrary high-order accuracy in time while preserving maximum-principle (MBP) and energy dissipating simultaneously. In this paper, we develop a new…

数值分析 · 数学 2025-11-04 Qing Cheng , Tingfeng Wang , Xiaofei Zhao