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In science, we are interested not only in forecasting but also in understanding how predictions are made, specifically what the interpretable underlying model looks like. Data-driven machine learning technology can significantly streamline…

符号计算 · 计算机科学 2025-05-29 Weiting Liu , Jiaxu Cui , Jiao Hu , En Wang , Bo Yang

We calculate the back reaction of cosmological perturbations on a general relativistic variable which measures the local expansion rate of the Universe. Specifically, we consider a cosmological model in which matter is described by a single…

广义相对论与量子宇宙学 · 物理学 2008-11-26 Ghazal Geshnizjani , Robert Brandenberger

Symbolic equations are at the core of scientific discovery. The task of discovering the underlying equation from a set of input-output pairs is called symbolic regression. Traditionally, symbolic regression methods use hand-designed…

机器学习 · 计算机科学 2021-06-14 Luca Biggio , Tommaso Bendinelli , Alexander Neitz , Aurelien Lucchi , Giambattista Parascandolo

We present a self-consistent mean field theory of the dynamo in 3D and turbulent diffusion in 2D in weakly ionized gas. We find that in 3D, the backreaction does not alter the beta effect while it suppresses the alpha effect when the…

天体物理学 · 物理学 2011-02-11 Nicolas Leprovost , Eun-Jin Kim

Symbolic regression is a machine learning technique that can learn the governing formulas of data and thus has the potential to transform scientific discovery. However, symbolic regression is still limited in the complexity and…

机器学习 · 计算机科学 2023-05-30 Michael Zhang , Samuel Kim , Peter Y. Lu , Marin Soljačić

Symbolic Regression (SR) offers an interpretable alternative to conventional Machine-Learning (ML) approaches, which are often criticized as ``black boxes''. In contrast to standard regression models that require a prescribed functional…

We introduce a generalization of the 4-dimensional averaging window function of Gasperini, Marozzi and Veneziano (2010) that may prove useful for a number of applications. The covariant nature of spatial scalar averaging schemes to address…

广义相对论与量子宇宙学 · 物理学 2019-02-28 Asta Heinesen , Pierre Mourier , Thomas Buchert

Reduced-rank regressions are powerful tools used to identify co-movements within economic time series. However, this task becomes challenging when we observe matrix-valued time series, where each dimension may have a different co-movement…

计量经济学 · 经济学 2024-07-12 Alain Hecq , Ivan Ricardo , Ines Wilms

Symbolic regression is emerging as a promising machine learning method for learning succinct underlying interpretable mathematical expressions directly from data. Whereas it has been traditionally tackled with genetic programming, it has…

机器学习 · 计算机科学 2025-01-14 Nour Makke , Sanjay Chawla

Identifying governing equations for a dynamical system is a topic of critical interest across an array of disciplines, from mathematics to engineering to biology. Machine learning -- specifically deep learning -- techniques have shown their…

动力系统 · 数学 2026-05-07 Nibodh Boddupalli , Timothy Matchen , Jeff Moehlis

Handling big data has largely been a major bottleneck in traditional statistical models. Consequently, when accurate point prediction is the primary target, machine learning models are often preferred over their statistical counterparts for…

统计方法学 · 统计学 2021-04-02 Arindam Fadikar , Stefan M. Wild , Jonas Chaves-Montero

This paper revisits datasets and evaluation criteria for Symbolic Regression (SR), specifically focused on its potential for scientific discovery. Focused on a set of formulas used in the existing datasets based on Feynman Lectures on…

机器学习 · 计算机科学 2025-01-06 Yoshitomo Matsubara , Naoya Chiba , Ryo Igarashi , Yoshitaka Ushiku

It has been suggested that the accelerated expansion of the Universe is due to backreaction of small scale density perturbations on the large scale spacetime geometry. While evidence against this suggestion has accumulated, it has not yet…

广义相对论与量子宇宙学 · 物理学 2008-09-16 Eran Rosenthal , Éanna É. Flanagan

We calculate photometric redshifts from the Sloan Digital Sky Survey Data Release 2 Galaxy Sample using artificial neural networks (ANNs). Different input patterns based on various parameters (e.g. magnitude, color index, flux information)…

天体物理学 · 物理学 2007-05-23 Lili Li , Yanxia Zhang , Yongheng Zhao , Dawei Yang

One of the outstanding problems in general relativistic cosmology is that of the averaging. That is, how the lumpy universe that we observe at small scales averages out to a smooth Friedmann-Lemaitre-Robertson-Walker (FLRW) model. The root…

宇宙学与河外天体物理 · 物理学 2016-11-21 Tharake Wijenayake , Weikang Lin , Mustapha Ishak

Using our recent proposal for defining gauge invariant averages we give a general-covariant formulation of the so-called cosmological "backreaction". Our effective covariant equations allow us to describe in explicitly gauge invariant form…

广义相对论与量子宇宙学 · 物理学 2010-04-14 M. Gasperini , G. Marozzi , G. Veneziano

The industrialization of catalytic processes hinges on the availability of reliable kinetic models for design, optimization, and control. Traditional mechanistic models demand extensive domain expertise, while many data-driven approaches…

计算工程、金融与科学 · 计算机科学 2025-07-04 Miguel Ángel de Carvalho Servia , Ilya Orson Sandoval , King Kuok , Hii , Klaus Hellgardt , Dongda Zhang , Ehecatl Antonio del Rio Chanona

We revisit the causal backreaction paradigm, in which the need for Dark Energy is eliminated via the generation of an apparent cosmic acceleration from the causal flow of inhomogeneity information coming in towards each observer from…

宇宙学与河外天体物理 · 物理学 2013-10-23 Brett Bochner

Computational fluid dynamics (CFD) analysis is widely used in engineering. Although CFD calculations are accurate, the computational cost associated with complex systems makes it difficult to obtain empirical equations between system…

流体动力学 · 物理学 2022-04-08 Mehrad Ansari , Heta A. Gandhi , David G. Foster , Andrew D. White

We introduce a spatial averaging scheme and use it to study the evolution of spatial averages in large-scale simulations of cosmological structure formation performed with the Einstein Toolkit. The averages are performed on the spatial…

宇宙学与河外天体物理 · 物理学 2024-10-15 Alexander Oestreicher , Sofie Marie Koksbang