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We consider a novel Bounce Universe model constructed within the framework of Horndeski gravity. We have analyzed the bispectrum of primordial scalar perturbations and evaluated the corresponding non-Gaussianities for this specific model.…

高能物理 - 理论 · 物理学 2025-08-26 Y. Ageeva , M. Kotenko , P. Petrov

Continuous-variable bosonic systems stand as prominent candidates for implementing quantum computational tasks. While various necessary criteria have been established to assess their resourcefulness, sufficient conditions have remained…

量子物理 · 物理学 2024-10-08 Cameron Calcluth , Nicolas Reichel , Alessandro Ferraro , Giulia Ferrini

This paper investigates new ways of estimating and identifying causal, noncausal, and mixed causal-noncausal autoregressive models driven by a non-Gaussian error sequence. We do not assume any parametric distribution function for the…

计量经济学 · 经济学 2022-11-28 Alain Hecq , Daniel Velasquez-Gaviria

Many-mode interacting Bose gases (1D,2D,3D) are simulated from first principles. The model uses a second-quantized Hamiltonian with two-particle interactions (possibly ranged), external potential, and interactions with an environment, with…

其他凝聚态物理 · 物理学 2009-09-29 Piotr Deuar

We use a generalized delta N formalism to study the generation of the primordial curvature perturbation in the curvaton brane scenario inspired by stringy compactifications. We note that the non-Gaussian features, especially the trispectra,…

高能物理 - 理论 · 物理学 2010-12-24 Yi-Fu Cai , Yi Wang

Macroscale continuum mechanics simulations rely on material properties stemming from the microscale, which are normally described using phenomenological equations of state (EOS). A method is proposed for the automatic generation of…

计算物理 · 物理学 2020-01-01 Oliver Strickson , Nikos Nikiforakis , Emilio Artacho

In recent years, diffusion models have gained popularity for their ability to generate higher-quality images in comparison to GAN models. However, like any other large generative models, these models require a huge amount of data,…

计算机视觉与模式识别 · 计算机科学 2023-12-21 Rajesh Shrestha , Bowen Xie

We present a computationally-efficient strategy to initialise the hyperparameters of a Gaussian process (GP) avoiding the computation of the likelihood function. Our strategy can be used as a pretraining stage to find initial conditions for…

机器学习 · 计算机科学 2023-04-27 Felipe Tobar , Elsa Cazelles , Taco de Wolff

Constructing a classical potential suited to simulate a given atomic system is a remarkably difficult task. This chapter presents a framework under which this problem can be tackled, based on the Bayesian construction of nonparametric force…

计算物理 · 物理学 2020-07-01 Aldo Glielmo , Claudio Zeni , Ádám Fekete , Alessandro De Vita

We present a numerical scheme for determining hyperboloidal initial data sets for the conformal field equations by using pseudo-spectral methods. This problem is split into two parts. The first step is the determination of a suitable…

广义相对论与量子宇宙学 · 物理学 2007-05-23 Jörg Frauendiener

It has been found that the primordial non-Gaussianity of the curvature perturbation in the case of non-Bunch-Davies initial states can be enhanced compared with those in the case of the Bunch-Davies one due to the interactions among the…

广义相对论与量子宇宙学 · 物理学 2020-07-15 Shingo Akama , Shin'ichi Hirano , Tsutomu Kobayashi

We analyze the non-Gaussianity for primordial curvature perturbations generated in multi-scalar slow-roll inflation model including the model with non-separable potential by making use of $\delta N$ formalism. Many authors have investigated…

天体物理学 · 物理学 2009-06-23 Shuichiro Yokoyama , Teruaki Suyama , Takahiro Tanaka

Thermography is especially valuable for the military and other users of surveillance cameras. Some recent methods based on Neural Radiance Fields (NeRF) are proposed to reconstruct the thermal scenes in 3D from a set of thermal and RGB…

计算机视觉与模式识别 · 计算机科学 2025-04-23 Rongfeng Lu , Hangyu Chen , Zunjie Zhu , Yuhang Qin , Ming Lu , Le Zhang , Chenggang Yan , Anke Xue

N-body simulations are essential for understanding the formation and evolution of structure in the Universe. However, the discrete nature of these simulations affects their accuracy when modelling collisionless systems. We introduce a new…

宇宙学与河外天体物理 · 物理学 2015-11-18 Oliver Hahn , Raul E. Angulo

We compute the non-Gaussianities that arise in single field, slow roll inflationary models arising from arbitrary homogeneous initial states, as well as subleading contributions to the power spectrum. Non Bunch-Davies vacuum initial states…

宇宙学与河外天体物理 · 物理学 2015-05-12 Sina Bahrami , Éanna É. Flanagan

Non-Gaussianity of the primordial density perturbations provides an important measure to constrain models of inflation. At cubic order the non-Gaussianity is captured by two parameters $\tau_{\rm NL}$ and $g_{\rm NL}$ that determine the…

宇宙学与河外天体物理 · 物理学 2015-08-12 Chang Feng , Asantha Cooray , Joseph Smidt , Jon O'Bryan , Brian Keating , Donough Regan

We present a fully probabilistic, physical model of the non-linearly evolved density field, as probed by realistic galaxy surveys. Our model is valid in the linear and mildly non-linear regimes and uses second order Lagrangian perturbation…

宇宙学与河外天体物理 · 物理学 2015-06-04 Jens Jasche , Benjamin D. Wandelt

In applied sciences, we often deal with deterministic simulation models that are too slow for simulation-intensive tasks such as calibration or real-time control. In this paper, an emulator for a generic dynamic model, given by a system of…

统计方法学 · 统计学 2012-07-06 Carlo Albert

Despite major methodological developments, Bayesian inference for Gaussian graphical models remains challenging in high dimension due to the tremendous size of the model space. This article proposes a method to infer the marginal and…

统计方法学 · 统计学 2018-04-10 Gwenaël G. R. Leday , Sylvia Richardson

Conventional cosmological initial condition generators are designed exclusively for fully periodic cubic domains and cannot produce the non-periodic, observer-centric configurations required by stereographically projected N-body codes such…

宇宙学与河外天体物理 · 物理学 2026-05-12 Balázs Pál , Gábor Rácz , István Csabai , István Szapudi