Malaise and remedy of binary boson-star initial data

Kavli Affiliate: Ulrich Sperhake | First 5 Authors: Thomas Helfer, Ulrich Sperhake, Robin Croft, Miren Radia, Bo-Xuan Ge | Summary: Through numerical simulations of boson-star head-on collisions, we explore the quality of binary initial data obtained from the superposition of single-star spacetimes. Our results demonstrate that evolutions starting from a plain superposition of individual boosted […]


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HERA Phase I Limits on the Cosmic 21-cm Signal: Constraints on Astrophysics and Cosmology During the Epoch of Reionization

Kavli Affiliate: George Efstathiou | First 5 Authors: The HERA Collaboration, Zara Abdurashidova, James E. Aguirre, Paul Alexander, Zaki Ali | Summary: Recently, the Hydrogen Epoch of Reionization Array (HERA) collaboration has produced the experiment’s first upper limits on the power spectrum of 21-cm fluctuations at z~8 and 10. Here, we use several independent theoretical […]


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Optimal multifrequency weighting for CMB lensing

Kavli Affiliate: Blake Sherwin | First 5 Authors: Noah Sailer, Emmanuel Schaan, Simone Ferraro, Omar Darwish, Blake Sherwin | Summary: Extragalactic foregrounds in Cosmic Microwave Background (CMB) temperature maps lead to significant biases in CMB lensing reconstruction if not properly accounted for. Combinations of multi-frequency data have been used to minimize the overall map variance […]


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Optimal multifrequency weighting for CMB lensing

Kavli Affiliate: Blake Sherwin | First 5 Authors: Noah Sailer, Emmanuel Schaan, Simone Ferraro, Omar Darwish, Blake Sherwin | Summary: Extragalactic foregrounds in Cosmic Microwave Background (CMB) temperature maps lead to significant biases in CMB lensing reconstruction if not properly accounted for. Combinations of multi-frequency data have been used to minimize the overall map variance […]


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What it Takes to Measure Reionization with Fast Radio Bursts

Kavli Affiliate: George Efstathiou | First 5 Authors: Stefan Heimersheim, Nina S. Sartorio, Anastasia Fialkov, Duncan R. Lorimer, | Summary: Fast Radio Bursts (FRBs) are recently-discovered extra-galactic radio transients which exhibit a distance-dependent dispersion of their signal, and thus can be used as cosmological probes. In this article we, for the first time, apply a […]


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21cmVAE: A VAE-based Emulator of the 21-cm Global Signal

Kavli Affiliate: George Efstathiou | First 5 Authors: Christian Hellum Bye, Stephen K. N. Portillo, Anastasia Fialkov, , | Summary: Considerable observational efforts are being dedicated to measuring the sky-averaged (global) 21-cm signal of neutral hydrogen from Cosmic Dawn and the Epoch of Reionization. Deriving observational constraints on the astrophysics of this era requires modelling […]


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21cmVAE: A Very Accurate Emulator of the 21-cm Global Signal

Kavli Affiliate: George Efstathiou | First 5 Authors: Christian H. Bye, Stephen K. N. Portillo, Anastasia Fialkov, , | Summary: Considerable observational efforts are being dedicated to measuring the sky-averaged (global) 21-cm signal of neutral hydrogen from Cosmic Dawn and the Epoch of Reionization. Deriving observational constraints on the astrophysics of this era requires modeling […]


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Shot noise and scatter in the star formation efficiency as a source of 21-cm fluctuations

Kavli Affiliate: George Efstathiou | First 5 Authors: Itamar Reis, Rennan Barkana, Anastasia Fialkov, , | Summary: The 21-cm signal from cosmic dawn and the epoch of reionization (EoR) probes the characteristics of the high redshift galaxy population. Many of the astrophysical properties of galaxies at high redshifts are currently unconstrained due to the lack […]


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Inference of the optical depth to reionization from low multipole temperature and polarisation Planck data

Kavli Affiliate: George Efstathiou | First 5 Authors: Roger de Belsunce, Steven Gratton, William Coulton, George Efstathiou, | Summary: This paper explores methods for constructing low multipole temperature and polarisation likelihoods from maps of the cosmic microwave background anisotropies that have complex noise properties and partial sky coverage. We use Planck 2018 High Frequency Instrument […]


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