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Uncertainty quantification for deep neural networks has recently evolved through many techniques. In this work, we revisit Laplace approximation, a classical approach for posterior approximation that is computationally attractive. However,…

Machine Learning · Computer Science 2021-07-14 Christian S. Perone , Roberto Pereira Silveira , Thomas Paula

Spectroscopic redshift surveys are key tools to trace the large-scale structure (LSS) of the Universe and test the $\Lambda$CDM model. However, using redshifts as distance proxies introduces distortions in the 3D galaxy distribution. If…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-09 Edoardo Maragliano , Punyakoti Ganeshaiah Veena , Giulia Degni , Enzo Franco Branchini

Statistical applications often involve the calculation of intractable multidimensional integrals. The Laplace formula is widely used to approximate such integrals. However, in high-dimensional or small sample size problems, the shape of the…

Computation · Statistics 2016-12-30 Erlis Ruli , Nicola Sartori , Laura Ventura

The cosmic deceleration parameter $q$ has been reconstructed in a non-parametric way using various combinations of recent observational datasets. The Pantheon compilation of the Supernova (SN) distance modulus data, the Cosmic Chronometer…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-16 Purba Mukherjee , Narayan Banerjee

We present a cosmic density field reconstruction method that augments the traditional reconstruction algorithms with a convolutional neural network (CNN). Following Shallue $\&$ Eisenstein (2022), the key component of our method is to use…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-05 Xinyi Chen , Fangzhou Zhu , Sasha Gaines , Nikhil Padmanabhan

The closely related issues of (1) reconstructing density and velocity fields from redshift survey and distance indicator data and (2) determining cosmological parameters from such data sets are discussed. I focus on possible explanations…

Astrophysics · Physics 2007-05-23 Jeffrey A. Willick

Advances in optical astrometry allow us to infer the non-radial kinematic structure of the Universe directly from observations. Here I use a supervised machine learning neural network method to predict 1.57 million redshifts based on…

Astrophysics of Galaxies · Physics 2025-07-03 Valeri V. Makarov

We compare two non-relativistic (NR) reduction schemes (heavy-fermion and Foldy-Wouthuysen) that are used to derive low-energy effective-field-theory Lagrangians. We give the explicit transformation between the two types of fields to…

Nuclear Theory · Physics 2008-11-26 A. Gardestig , K. Kubodera , F. Myhrer

We present a new method for extracting the true 3-d velocity and density fields from the nonlinear redshift--space projected density field. The method is based on the nonlinear, nonlocal transformation of the density field. We assume a…

Astrophysics · Physics 2015-06-24 A. N. Taylor , M. Rowan-Robinson

There is a growing attention given to utilizing Lagrangian and Hamiltonian mechanics with network training in order to incorporate physics into the network. Most commonly, conservative systems are modeled, in which there are no frictional…

Machine Learning · Computer Science 2024-05-28 Veera Sundararaghavan , Megna N. Shah , Jeff P. Simmons

We address the problem of inferring the three-dimensional matter distribution from a sparse set of one-dimensional quasar absorption spectra of the Lyman-$\alpha$ forest. Using a Bayesian forward modelling approach, we focus on extending…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-14 Natalia Porqueres , Oliver Hahn , Jens Jasche , Guilhem Lavaux

An algorithm to estimate motion from satellite imagery is presented. Dense displacement fields are computed from time-separated images of of significant convective activity using a Bayesian formulation of the motion estimation problem.…

Atmospheric and Oceanic Physics · Physics 2007-05-23 Sai Ravela , Virat Chatdarong

Reconstructing the matter density field from galaxy counts is a problem frequently addressed in current literature. Two main sources of error are shot noise from galaxy counts and insufficient knowledge of the correct galaxy position caused…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Cornelius Weig , Torsten Ensslin

We consider the reconstruction problem in compressed sensing in which the observations are recorded in a finite number of bits. They may thus contain quantization errors (from being rounded to the nearest representable value) and saturation…

Machine Learning · Statistics 2013-10-11 Ji Liu , Stephen J. Wright

(abridged) Observations of Faraday rotation for extragalactic sources probe magnetic fields both inside and outside the Milky Way. Building on our earlier estimate of the Galactic contribution, we set out to estimate the extragalactic…

A forward model of matter and biased tracers at arbitrary order in Lagrangian perturbation theory (LPT) is presented. The forward model contains the complete LPT displacement field at any given order in perturbations, as well as all…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-04 Fabian Schmidt

Received signal strength based radio tomographic imaging is a popular device-free indoor localization method which reconstructs the spatial loss field of the environment using measurements from a dense wireless network. Existing methods…

Emerging Technologies · Computer Science 2016-04-12 Hüseyin Yiğitler , Riku Jäntti , Ossi Kaltiokallio , Neal Patwari

Data dependent regularization is known to benefit a wide variety of problems in machine learning. Often, these regularizers cannot be easily decomposed into a sum over a finite number of terms, e.g., a sum over individual example-wise…

Computer Vision and Pattern Recognition · Computer Science 2019-09-30 Sathya N. Ravi , Abhay Venkatesh , Glenn Moo Fung , Vikas Singh

Large scale density modes are difficult to measure because they are sensitive to systematic observational errors in galaxy surveys, but we can study them indirectly by observing their impact on small scale perturbations. Cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-08 Peikai Li , Scott Dodelson , Rupert A. C. Croft

A weighted, semi-discrete, fast optimal transport (OT) algorithm for reconstructing the Lagrangian positions of proto-halos from their evolved Eulerian positions is presented. The algorithm makes use of a mass estimate of the biased tracers…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-10 Farnik Nikakhtar , Ravi K. Sheth , Bruno Lévy , Roya Mohayaee
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