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We derive optimal estimators for the two-, three-, and four-point correlators of statistically isotropic scalar fields defined on the sphere, such as the Cosmic Microwave Background temperature fluctuations, allowing for arbitrary (linear)…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-28 Oliver H. E. Philcox

We present a Fisher information study of the statistical impact of galaxy bias and selection effects on the estimation of key cosmological parameters from galaxy redshift surveys; in particular, the angular diameter distance, Hubble…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-12 Nishant Agarwal , Vincent Desjacques , Donghui Jeong , Fabian Schmidt

We present a novel approach to analyzing astronomical spectral survey data using our non-linear extension of an online dictionary learning algorithm. Current and upcoming surveys such as SPHEREx will use spectral data to build a 3D map of…

Instrumentation and Methods for Astrophysics · Physics 2023-11-28 Sean Bryan , Ayan Barekzai , Delondrae Carter , Philip Mauskopf , Julian Mena , Danielle Rivera , Abel S. Uriarte , Pao-Yu Wang

We introduce a publicly available full-sky beam convolution code library intended to inform the design of future cosmic microwave background (CMB) instruments and help current experiments probe potential systematic effects. The code can be…

Instrumentation and Methods for Astrophysics · Physics 2019-05-08 Adriaan J. Duivenvoorden , Jon E. Gudmundsson , Alexandra S. Rahlin

Evidence that the Universe may be close to the critical density, required for its expansion eventually to be halted, comes principally from dynamical studies of large-scale structure. These studies either use the observed peculiar velocity…

Astrophysics · Physics 2015-06-24 S. Matarrese , L. Verde , A. Heavens

We present the Bayesian Global Sky Model (B-GSM), a new absolutely calibrated model of the diffuse Galactic foreground at frequencies below 408 MHz. We assemble a dataset of publicly available diffuse emission maps at frequencies between 45…

Instrumentation and Methods for Astrophysics · Physics 2025-04-08 George Carter , Will Handley , Mark Ashdown , Nima Razavi-Ghods

The existing algorithms for processing skyline queries cannot adapt to big data. This paper proposes two approximate skyline algorithms based on sampling. The first algorithm obtains a fixed size sample and computes the approximate skyline…

Databases · Computer Science 2020-10-16 Xingxing Xiao , Jianzhong Li

This article proposes a generic framework to process jointly the spatial and spectral information of hyperspectral images. First, sub-images are extracted. Then each of these sub-images follows two parallel workflows, one dedicated to the…

The power spectrum estimated from a galaxy redshift survey is the real spectrum convolved with a window function, so when estimating the power on very large scales (for small k), it is important that this window function be as narrow as…

Astrophysics · Physics 2009-10-07 Max Tegmark

Provided a random realization of the cosmological model, observations of our cosmic neighborhood now allow us to build simulations of the latter down to the non-linear threshold. The resulting local Universe models are thus accurate up to a…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-10 Jenny G. Sorce

We introduce and analyze the concept of space-spectrum uncertainty for certain commonly-used designs for spectrally programmable cameras. Our key finding states that, it is impossible to simultaneously capture high-resolution spatial images…

Image and Video Processing · Electrical Eng. & Systems 2021-01-01 Vishwanath Saragadam , Aswin Sankaranarayanan

We seek to improve the accuracy of joint galaxy photometric redshift estimation and spectral energy distribution (SED) fitting. By simulating different sources of uncorrected systematic errors, we demonstrate that if the uncertainties on…

Instrumentation and Methods for Astrophysics · Physics 2015-06-24 Viviana Acquaviva , Anand Raichoor , Eric Gawiser

We present a numerically cheap approximation to super-sample covariance (SSC) of large scale structure cosmological probes, first in the case of angular power spectra. It necessitates no new elements besides those used for the prediction of…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-17 Fabien Lacasa , Julien Grain

Forward modeling the galaxy density within the Effective Field Theory of Large Scale Structure (EFT of LSS) enables field-level analyses that are robust to theoretical uncertainties. At the same time, they can maximize the constraining…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-08 Julia Stadler , Fabian Schmidt , Martin Reinecke , Matteo Esposito

Within the context of upcoming full-sky lensing surveys, the edge-preserving non- linear algorithm Aski is presented. Using the framework of Maximum A Posteriori inversion, it aims at recovering the full-sky convergence map from surveys…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 C. Pichon , E. Thiebaut , S. Prunet , K. Benabed , S. Colombi , T. Sousbie , R. Teyssier

We study the bispectrum in the Effective Field Theory of Large Scale Structure, consistently accounting for the effects of short-scale dynamics. We begin by proving that, as long as the theory is perturbative, it can be formulated to…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Tobias Baldauf , Lorenzo Mercolli , Mehrdad Mirbabayi , Enrico Pajer

Obtaining accurate photometric redshift estimations is an important aspect of cosmology, remaining a prerequisite of many analyses. In creating novel methods to produce redshift estimations, there has been a shift towards using machine…

Instrumentation and Methods for Astrophysics · Physics 2021-07-07 Ben Henghes , Connor Pettitt , Jeyan Thiyagalingam , Tony Hey , Ofer Lahav

Airborne laser scanning (LiDAR) point clouds over large forested areas can be processed to segment individual trees and subsequently extract tree-level information. Existing segmentation procedures typically detect more than 90% of…

Computer Vision and Pattern Recognition · Computer Science 2017-08-04 Hamid Hamraz , Marco A. Contreras , Jun Zhang

We propose an efficient algorithm for reconstructing one-dimensional wide-band line spectra from their Fourier data in a bounded interval $[-\Omega,\Omega]$. While traditional subspace methods such as MUSIC achieve super-resolution for…

Signal Processing · Electrical Eng. & Systems 2023-10-30 Zetao Fei , Hai Zhang

Large galaxy surveys demand fast and scalable estimators for anisotropic clustering statistics beyond the monopole. We present a suite of efficient FFT-based estimators for power-spectrum and bispectrum multipoles, built upon exact…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-07 Yunchen Xie , Ruiyang Zhao , Gan Gu , Xiaoma Wang , Xiaoyong Mu , Yuting Wang , Gong-Bo Zhao , Florian Beutler , John A. Peacock