Darcy Barron
A5081126606- Radio Astronomy Observations and Technology
- Cosmology and Gravitation Theories
- Superconducting and THz Device Technology
- Dark Matter and Cosmic Phenomena
- Geophysics and Gravity Measurements
- Astrophysics and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- Physics of Superconductivity and Magnetism
- Astronomy and Astrophysical Research
- Precipitation Measurement and Analysis
- Advanced Thermodynamic Systems and Engines
- Adaptive optics and wavefront sensing
- Computational Physics and Python Applications
- Astrophysics and Star Formation Studies
- Climate variability and models
- Solar and Space Plasma Dynamics
- Radio Frequency Integrated Circuit Design
- Health and Medical Research Impacts
- Microwave Engineering and Waveguides
- Spacecraft Design and Technology
- Astronomical Observations and Instrumentation
- Particle Accelerators and Free-Electron Lasers
- Technology Assessment and Management
- Meteorological Phenomena and Simulations
- Ionosphere and magnetosphere dynamics
University of New Mexico
2018-2025
University of California, Berkeley
2014-2020
University of California, San Diego
2010-2018
Argonne National Laboratory
2016
Université Claude Bernard Lyon 1
2014
Lawrence Berkeley National Laboratory
2014
McGill University
2014
Institut de Biologie et de Chimie des Protéines
2014
Cardiff University
2014
University of Illinois Urbana-Champaign
2008
The Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations the early 2020s. We describe scientific goals of experiment, motivate design, and forecast its performance. SO will measure temperature polarization anisotropy six frequency bands: 27, 39, 93, 145, 225 280 GHz. initial configuration have three small-aperture 0.5-m telescopes (SATs) one large-aperture 6-m telescope (LAT), with total 60,000 cryogenic...
We present the science case, reference design, and project plan for Stage-4 ground-based cosmic microwave background experiment CMB-S4.
We report a measurement of the B-mode polarization power spectrum in cosmic microwave background (CMB) using Polarbear experiment Chile. The faint signature carries information about universe's entire history gravitational structure formation, and inflation that may have occurred very early universe. Our covers angular multipole range 500 < ℓ 2100 is based on observations an effective sky area 25 with 35 resolution at 150 GHz. On these scales, lensing CMB by intervening universe expected to...
Abstract CMB-S4—the next-generation ground-based cosmic microwave background (CMB) experiment—is set to significantly advance the sensitivity of CMB measurements and enhance our understanding origin evolution universe. Among science cases pursued with CMB-S4, quest for detecting primordial gravitational waves is a central driver experimental design. This work details development forecasting framework that includes power-spectrum-based semianalytic projection tool, targeted explicitly toward...
Distortion of the cosmic microwave background by matter in universe, known as gravitational lensing, is observed POLARBEAR collaboration. The technique used here would allow for all gravitating to be mapped, and provide important corrections detection primordial waves background.
Abstract We report an improved measurement of the cosmic microwave background B -mode polarization power spectrum with Polarbear experiment at 150 GHz. By adding new data collected during second season observations (2013–2014) to re-analyzed from first (2012–2013), we have reduced twofold band-power uncertainties. The band powers are reported over angular multipoles , where dominant signal is expected be due gravitational lensing E -modes. reject null hypothesis no a confidence 3.1 σ...
We constrain anisotropic cosmic birefringence using four-point correlations of even-parity $E$-mode and odd-parity $B$-mode polarization in the microwave background measurements made by POLARization Background Radiation (POLARBEAR) experiment its first season observations. find that signal from any parity-violating processes is consistent with zero. The Faraday rotation can be compared equivalent quantity generated primordial magnetic fields if they existed. POLARBEAR nondetection translates...
A new technique, first performed using the South Pole Telescope, that allows gravitational deflections of cosmic microwave background to be measured from photon polarization, gets further support measurements by POLARBEAR collaboration.
The Simons Observatory (SO) is a ground-based cosmic microwave background (CMB) experiment sited on Cerro Toco in the Atacama Desert Chile that promises to provide breakthrough discoveries fundamental physics, cosmology, and astrophysics. Supported by Foundation, Heising-Simons with contributions from collaborating institutions, SO will see first light 2021 start five year survey 2022. has 287 collaborators 12 countries 53 including 85 students 90 postdocs. its currently funded form...
We present the design and characterization of POLARBEAR experiment. will measure polarization cosmic microwave background (CMB) on angular scales ranging from experiment's 3.5 arcminute beam size to several degrees. The experiment utilizes a unique focal plane 1,274 antenna-coupled, sensitive TES bolometers cooled 250 milliKelvin. Employing this along with stringent control over systematic errors, has sensitivity detect expected small scale B-mode signal due gravitational lensing search for...
The Simons Observatory (SO) will make precise temperature and polarization measurements of the cosmic microwave background (CMB) using a set telescopes which cover angular scales between 1 arcminute tens degrees, contain over 60,000 detectors, observe at frequencies 27 270 GHz. SO consist 6 m aperture telescope coupled to 30,000 transition-edge sensor bolometers along with three 42 cm refractive telescopes, an additional 30,000+ all be located in Atacama Desert altitude 5190 m. powerful...
POLARBEAR-2 (PB-2) is a cosmic microwave background (CMB) polarization experiment that will be located in the Atacama highland Chile at an altitude of 5200 m. Its science goals are to measure CMB signals originating from both primordial gravitational waves and weak lensing. PB-2 designed tensor scalar ratio, r, with precision {\sigma}(r) < 0.01, sum neutrino masses, {\Sigma}m{\nu}, {\sigma}({\Sigma}m{\nu}) 90 meV. To achieve these goals, employ 7588 transition-edge sensor bolometers 95 GHz...
The hot dense environment of the early universe is known to have produced large numbers baryons, photons, and neutrinos. These extreme conditions may also other long-lived species, including new light particles (such as axions or sterile neutrinos) gravitational waves. effects any such relics can be observed through their unique imprint in cosmic microwave background (CMB), large-scale structure, primordial element abundances, are important determining initial universe. We argue that future...
Abstract At millimeter wavelengths, the atmospheric emission is circularly polarized owing to Zeeman splitting of molecular oxygen by Earth's magnetic field. We report a measurement signal in 150 GHz band using 3 yr observational data with Polarbear project. Nonidealities continuously rotating half-wave plate (HWP) partially convert light linearly light. While detectors are sensitive linear polarization, this effect makes them circular polarization. Although was not intended use, we utilized...
Abstract We present the detection and characterization of fluctuations in linearly polarized emission from atmosphere above South Pole. These measurements make use data SPT-3G receiver on Pole Telescope three frequency bands centered at 95, 150, 220 GHz. cross-correlation between detectors to produce an unbiased estimate power Stokes I , Q U parameters large angular scales. Our results are consistent with signal being produced by combination Rayleigh scattering thermal radiation ground a...
The Polarbear Cosmic Microwave Background (CMB) polarization experiment is currently observing from the Atacama Desert in Northern Chile. It will characterize expected B-mode due to gravitational lensing of CMB, and search for possible signature inflationary waves. Its 250 mK focal plane detector array consists 1,274 polarization-sensitive antenna-coupled bolometers, each with an associated lithographed band-defining filter. Each detector's planar antenna structure coupled telescope's...
Using only cosmic microwave background polarization data from the POLARBEAR experiment, we measure $B$-mode delensing on subdegree scales at more than $5\sigma$ significance. We achieve a 14% power variance reduction, highest to date for internal delensing, and improve this result 2% by applying first time an iterative maximum posteriori method. Our analysis demonstrates capability of as means improving constraints inflationary models, paving way optimal next-generation primordial experiments.
Abstract We quantify the calibration requirements for systematic uncertainties next-generation ground-based observatories targeting large-angle B-mode polarization of Cosmic Microwave Background, with a focus on Simons Observatory (SO). explore gain calibration, bandpass center frequencies, and angles, including frequency variation latter across bandpass. find that frequencies must be known to percent levels or less avoid biases tensor-to-scalar ratio r order Δ r∼10 -3 , in line previous...
Very light pseudoscalar fields, often referred to as axions, are compelling dark matter candidates and can potentially be detected through their coupling the electromagnetic field. Recently a novel detection technique using cosmic microwave background (CMB) was proposed, which relies on fact that axion field oscillates at frequency equal its mass in appropriate units, leading time-dependent birefringence. For oscillation periods this allows telescope via induced sinusoidal of CMB linear...
The Simons Array is an expansion of the POLARBEAR cosmic microwave background (CMB) polarization experiment currently observing from Atacama Desert in Northern Chile. This will create array three 3.5m telescopes each coupled to a multichroic bolometric receiver. have sensitivity produce ≥ 5σ detection inationary gravitational waves with tensor-to-scalar ratio r 0:01, detect known minimum 58 meV sum neutrino masses 3σ confidence when combined next-generation baryon acoustic oscillation...