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In this follow-up work to the High Energy Physics Community Summer Study 2013 (HEP CSS 2013, a.k.a. Snowmass), we explore the scientific capabilities of a future Stage-IV Cosmic Microwave Background polarization experiment (CMB-S4) under…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-11 W. L. K. Wu , J. Errard , C. Dvorkin , C. L. Kuo , A. T. Lee , P. McDonald , A. Slosar , O. Zahn

The EDGES collaboration reported the finding of an unexpectedly deep absorption in the radio background at 78 MHz and interpreted the dip as a first detection of redshifted 21-cm from Cosmic Dawn. We have attempted an alternate analysis,…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-31 Saurabh Singh , Ravi Subrahmanyan

Late time cosmic acceleration may be achieved by modifying gravity on large scales. This should also have consequences on the evolution of perturbations. We thus extend our study of exponential infrared $f(T)$ teleparallel gravity to…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-11 Mahmoud Hashim , Amr A. El-Zant , Waleed El Hanafy , Alexey Golovnev

Power spectrum estimators are an important tool in efforts to detect the 21 cm brightness temperature fluctuations from neutral hydrogen at early times. An initial detection will likely be statistical in nature, meaning that it will not be…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-24 Jacob Burba , Philip Bull , Michael J. Wilensky , Fraser Kennedy , Hugh Garsden , Katrine A. Glasscock

We estimate the magnitude of the bias due to non-Gaussian extragalactic foregrounds on the optimal reconstruction of the cosmic microwave background (CMB) lensing potential and temperature power spectra. The reconstruction is performed…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-25 M. Doohan , M. Millea , S. Raghunathan , F. Ge , L. Knox , K. Prabhu , C. L. Reichardt , W. L. K. Wu

We propose counting peaks in weak lensing (WL) maps, as a function of their height, to probe models of dark energy and to constrain cosmological parameters. Because peaks can be identified in two-dimensional WL maps directly, they can…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-06 Jan M. Kratochvil , Zoltán Haiman , Morgan May

We introduce new CosmoEJS modules to improve the investigation of the consequences of constraints on the parameter values of cosmological models. We use CosmoMC to fit dark energy models and modified gravity models to recent data from the…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-14 Jacob Moldenhauer , Francis Cavanna , William O'toole , William Zimmerman

We present constraints on extensions to the flat $\Lambda$CDM cosmological model by varying the spatial curvature $\Omega_K$, the sum of the neutrino masses $\sum m_\nu$, the dark energy equation of state parameter $w$, and the Hu-Sawicki…

Current cosmological analyses which use Type Ia supernova (SN Ia) observations combine SN samples to expand the redshift range beyond that of a single sample and increase the overall sample size. The inhomogeneous photometric calibration…

We perform a combined analysis of cosmic shear tomography, galaxy-galaxy lensing tomography, and redshift-space multipole power spectra (monopole and quadrupole) using 450 deg$^2$ of imaging data by the Kilo Degree Survey (KiDS) overlapping…

We developed a convolutional neural network (CNN) model to distinguish the double-lined spectroscopic binaries (SB2s) from others based on single exposure medium-resolution spectra ($R\sim 7,500$). The training set consists of a large set…

We introduce the Bayesian Global Sky Model (B-GSM), a novel data-driven Bayesian approach to modelling radio foregrounds at frequencies <400~MHz. B-GSM aims to address the limitations of previous models by incorporating robust error…

Instrumentation and Methods for Astrophysics · Physics 2025-11-12 George Carter , Will Handley , Mark Ashdown , Nima Razavi-Ghods

In the paper we check whether the contribution of $(-)(1+z)^6$ type in the Friedmann equation can be tested. We consider some astronomical tests to constrain the density parameters in such models. We describe different interpretations of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Marek Szydlowski , Wlodzimierz Godlowski , Tomasz Stachowiak

We measure the cosmic shear power spectrum on large angular scales by cross-correlating the shapes of ~9 million galaxies measured in the optical SDSS survey with the shapes of ~2.7x10^5 radio galaxies measured by the overlapping VLA-FIRST…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-27 Constantinos Demetroullas , Michael L. Brown

Measurements of cosmic microwave background spectral distortions have profound implications for our understanding of physical processes taking place over a vast window in cosmological history. Foreground contamination is unavoidable in such…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-03 Maximilian H. Abitbol , Jens Chluba , J. Colin Hill , Bradley R. Johnson

Detection of millikelvin-level signals from the 'Cosmic Dawn' requires an unprecedented level of sensitivity and systematic calibration. We report the theory behind a novel calibration algorithm developed from the formalism introduced by…

Instrumentation and Methods for Astrophysics · Physics 2022-09-15 I. L. V. Roque , W. J. Handley , N. Razavi-Ghods

Inferring stellar parameters and chemical abundances by forward modeling stellar spectra usually requires a spectral synthesis code, or an emulator constructed from a curated training set. In these situations continuum normalization is…

Solar and Stellar Astrophysics · Physics 2026-01-29 Andrew R. Casey , Adam Wheeler , Megan Bedell , David W. Hogg , Andrew Sayjdari , Lily Zhao

Cosmography has been referred to as a solution to the inverse scattering problem, which is reasonable since it allows us to calculate cosmological bounds from data samplers by performing an expansion of the cosmological observables around…

General Relativity and Quantum Cosmology · Physics 2021-01-11 Cristian Zamora Munõz , Celia Escamilla-Rivera

One approach to extracting the global 21-cm signal from total-power measurements at low radio frequencies is to parametrize the different contributions to the data and then fit for these parameters. We examine parametrizations of the 21-cm…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-04 Geraint J. A. Harker , Jordan Mirocha , Jack O. Burns , Jonathan R. Pritchard

Extracting parameters from the global 21cm signal is crucial for understanding the early Universe. However, detecting the 21cm signal is challenging due to the brighter foreground and associated observational difficulties. In this study, we…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-16 Anshuman Tripathi , Abhirup Datta , Gursharanjit Kaur