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相关论文: Cosmological Structure Formation with Augmented La…

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We present a method for reconstructing cosmological densityn for and velocity fields using the Lagrangian Zel'dovich formalism. . The method involves finding the least action solution for straight line particle paths in an evolving density…

天体物理学 · 物理学 2015-06-24 R. A. C. Croft , E. Gaztanaga

The Newtonian Lagrangian perturbation theory is a widely used framework to study structure formation in cosmology in the nonlinear regime. We review a general-relativistic formulation of such a perturbation approach, emphasizing results on…

广义相对论与量子宇宙学 · 物理学 2022-11-10 Thomas Buchert , Ismael Delgado Gaspar , Jan J. Ostrowski

Embedding tables are usually huge in click-through rate (CTR) prediction models. To train and deploy the CTR models efficiently and economically, it is necessary to compress their embedding tables at the training stage. To this end, we…

机器学习 · 计算机科学 2024-08-07 Shiwei Li , Huifeng Guo , Lu Hou , Wei Zhang , Xing Tang , Ruiming Tang , Rui Zhang , Ruixuan Li

Understanding the formation and evolution of large-scale structure is a central problem in cosmology and enables precise tests of General Relativity on cosmological scales and constraints on dark energy. An essential ingredient is an…

宇宙学与河外天体物理 · 物理学 2015-06-16 Lile Wang , Beth Reid , Martin White

We introduce a Lagrangian-space Effective Field Theory (LEFT) formalism for the study of cosmological large scale structures. Unlike the previous Eulerian-space construction, it is naturally formulated as an effective field theory of…

宇宙学与河外天体物理 · 物理学 2015-06-17 Rafael A. Porto , Leonardo Senatore , Matias Zaldarriaga

Using the spherical collapse approach, we investigate the impact of two alternative dark matter models, each characterized by distinct non-zero equations of state, one constant and the other time dependent on the nonlinear regime.…

宇宙学与河外天体物理 · 物理学 2024-10-22 Zahra Davari , Amjad Ashoorioon , Kazem Rezazadeh

The Effective Field Theory of Large-Scale Structure (EFTofLSS) attempts to amend some of the shortcomings of the traditional perturbative methods used in cosmology. It models the evolution of long-wavelength perturbations above a cutoff…

宇宙学与河外天体物理 · 物理学 2024-08-15 Mandar Karandikar , Cristiano Porciani , Oliver Hahn

We analyzed the performance of a perturbation theory for nonlinear cosmological dynamics, based on the Lagrangian description of hydrodynamics. In our previous paper, we solved hydrodynamic equations for a self-gravitating fluid with…

天体物理学 · 物理学 2009-11-10 Takayuki Tatekawa

Generating motions for robots interacting with objects of various shapes is a complex challenge, further complicated by the robot geometry and multiple desired behaviors. While current robot programming tools (such as inverse kinematics,…

机器人学 · 计算机科学 2025-06-19 Xuemin Chi , Hakan Girgin , Tobias Löw , Yangyang Xie , Teng Xue , Jihao Huang , Cheng Hu , Zhitao Liu , Sylvain Calinon

Semi-analytical methods, based on Eulerian perturbation theory, are a promising tool to follow the time evolution of cosmological perturbations at small redshifts and at mildly nonlinear scales. All these schemes are based on two…

宇宙学与河外天体物理 · 物理学 2015-05-30 Massimo Pietroni , Gianpiero Mangano , Ninetta Saviano , Matteo Viel

We perform numerical evolutions of cosmological scenarios using a standard general relativistic code in spherical symmetry. We concentrate on two different situations: initial matter distributions that are homogeneous and isotropic, and…

广义相对论与量子宇宙学 · 物理学 2014-12-09 Jose M. Torres , Miguel Alcubierre , Alberto Diez-Tejedor , Dario Nunez

The late-time nonlinear Lagrangian displacement field is highly correlated with the initial field, so reconstructing it could enable us to extract primordial cosmological information. Our previous work [1] carefully studied the displacement…

宇宙学与河外天体物理 · 物理学 2024-01-25 Atsuhisa Ota , Hee-Jong Seo , Shun Saito , Florian Beutler

Here we present a simple, parameter-free, non-perturbative algorithm that gives low-redshift cosmological particle realizations accurate to few-Megaparsec scales, called MUSCLE (MUltiscale Spherical ColLapse Evolution). It has virtually the…

宇宙学与河外天体物理 · 物理学 2015-10-28 Mark C. Neyrinck

Traditional N-body methods introduce localised perturbations in the gravitational forces governing their evolution. These perturbations lead to an artificial fragmentation in the filamentary network of the Large Scale Structure, often…

宇宙学与河外天体物理 · 物理学 2025-08-28 Robert A. Mostoghiu Paun , Darren Croton , Chris Power , Alexander Knebe , Adam J. Ussing , Alan R. Duffy

Low-rank plus diagonal (LRPD) decompositions provide a powerful structural model for large covariance matrices, simultaneously capturing global shared factors and localized corrections that arise in covariance estimation, factor analysis,…

数值分析 · 数学 2025-12-22 Kingsley Yeon , Mihai Anitescu

The goal of generative models is to learn the intricate relations between the data to create new simulated data, but current approaches fail in very high dimensions. When the true data generating process is based on physical processes these…

宇宙学与河外天体物理 · 物理学 2021-04-28 Biwei Dai , Uros Seljak

We update Halo Zeldovich Perturbation Theory (HZPT), an analytic model for the two-point statistics of dark matter, to describe halo and galaxy clustering, and galaxy-matter cross-correlation on nonlinear scales. The model correcting…

宇宙学与河外天体物理 · 物理学 2024-06-11 James M. Sullivan , Uros Seljak , Sukhdeep Singh

Associating the formation sites of haloes with the maxima of the smoothed linear density field, we present non-perturbative predictions for the Lagrangian and evolved halo correlation functions that are valid at all separations. In…

宇宙学与河外天体物理 · 物理学 2021-05-05 Tobias Baldauf , Sandrine Codis , Vincent Desjacques , Christophe Pichon

We derive a semi-analytical extension of the spherical collapse model of structure formation that takes account of the effects of deviations from spherical symmetry and shell crossing which are important in the non-linear regime. Our model…

天体物理学 · 物理学 2008-11-26 Douglas J. Shaw , David F. Mota

This work presents a formalism for deriving likelihoods of the cosmological density field directly from first principles within Perturbation Theory (PT). By assuming a perturbative expansion around the Gaussian initial density field and…

宇宙学与河外天体物理 · 物理学 2025-05-30 Rodrigo Voivodic