P. Daniel Meerburg
A5001891734- Cosmology and Gravitation Theories
- Radio Astronomy Observations and Technology
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Superconducting and THz Device Technology
- Black Holes and Theoretical Physics
- Astronomy and Astrophysical Research
- Geophysics and Gravity Measurements
- Pulsars and Gravitational Waves Research
- Solar and Space Plasma Dynamics
- Computational Physics and Python Applications
- Scientific Research and Discoveries
- Relativity and Gravitational Theory
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Climate variability and models
- Advanced Thermodynamics and Statistical Mechanics
- Particle physics theoretical and experimental studies
- Methane Hydrates and Related Phenomena
- Astronomical Observations and Instrumentation
- Space Science and Extraterrestrial Life
- Earth Systems and Cosmic Evolution
- Radio Wave Propagation Studies
- Antenna Design and Optimization
University of Groningen
2018-2025
University of Cambridge
2018-2021
Canadian Institute for Theoretical Astrophysics
2015-2018
University of Toronto
2014-2018
University of Bonn
2018
Cornell University
2018
Universidad Católica de la Santísima Concepción
2018
Astronomy and Space
2018
Princeton University
2013-2015
Princeton Public Schools
2014
This book lays out the scientific goals to be addressed by next-generation ground-based cosmic microwave background experiment, CMB-S4, envisioned consist of dedicated telescopes at South Pole, high Chilean Atacama plateau and possibly a northern hemisphere site, all equipped with new superconducting cameras. CMB-S4 will dramatically advance cosmological studies crossing critical thresholds in search for B-mode polarization signature primordial gravitational waves, determination number...
Modifications of the initial-state inflaton field can induce a departure from Gaussianity and leave testable imprint on higher order correlations CMB large scale structures in Universe. We focus bispectrum statistics primordial curvature perturbation its projection CMB. For canonical single-field action three-point correlator enhancement is localized, maximizing collinear limit, corresponding to enfolded or squashed triangles comoving momentum space. show that available local equilateral...
Abstract We present a detailed overview of the science goals and predictions for Prime-Cam direct-detection camera–spectrometer being constructed by CCAT-prime collaboration dedicated use on Fred Young Submillimeter Telescope (FYST). The FYST is wide-field, 6 m aperture submillimeter telescope built (first light in late 2023) an international consortium institutions led Cornell University sited at more than 5600 Cerro Chajnantor northern Chile. one two instruments planned will provide...
Models of axion inflation are particularly interesting since they provide a natural justification for the flatness potential over super-Planckian distance, namely approximate shift-symmetry inflaton. In addition, most observational consequences directly related to this symmetry and hence correlated. Large tensor modes can be accompanied by observable effects shift-symmetric coupling ϕF gauge field. During leads copious production quanta consequently very distinct modification primordial...
In this second of two papers we apply our recently developed code to search for resonance features in the Planck CMB temperature data. We both log-spaced oscillations or linear-spaced and compare findings with results WMAP9 analysis team [P. A. R. Ade et al. (Planck Collaboration), arXiv:1303.5082]. While there are hints resonant present data, significance these weaken more With accurate small scale measurements, also find that best-fit frequency has shifted amplitude been reduced. confirm...
A millimeter-wave survey over half the sky, that spans frequencies in range of 30 to 350 GHz, and is both an order magnitude deeper higher-resolution than currently funded surveys would yield enormous gain understanding fundamental physics astrophysics. By providing such a deep, high-resolution (about 0.5 uK-arcmin noise 15 arcsecond resolution at 150 GHz), CMB-HD will enable major advances. It allow 1) use gravitational lensing primordial microwave background map distribution matter on...
Our current understanding of the Universe is established through pristine measurements structure in cosmic microwave background (CMB) and distribution shapes galaxies tracing large scale (LSS) Universe. One key ingredient that underlies cosmological observables field sources observed assumed to be initially Gaussian with high precision. Nevertheless, a minimal deviation from Gaussianityis perhaps most robust theoretical prediction models explain Universe; itis necessarily present even...
Inflation may provide unique insight into the physics at highest available energy scales that cannot be replicated in any realistic terrestrial experiment. Features primordial power spectrum are generically predicted a wide class of models inflation and its alternatives, observationally one most overlooked channels for finding evidence non-minimal inflationary models. Constraints from observations cosmic microwave background cover widest range feature frequencies, but sensitive constraints...
Our current understanding of the Universe is established through pristine measurements structure in cosmic microwave background (CMB) and distribution shapes galaxies tracing large scale (LSS) Universe. One key ingredient that underlies cosmological observables field sources observed assumed to be initially Gaussian with high precision. Nevertheless, a minimal deviation from Gaussianityis perhaps most robust theoretical prediction models explain Universe; itis necessarily present even...
Abstract In this work we analyse in detail the possibility of using small and intermediate-scale gravitational wave anisotropies to constrain inflationary particle content. First, develop a phenomenological approach focusing on generated by primordial tensor-tensor-scalar purely non-Gaussianities. We highlight quantities that play key role determining detectability signal. To amplify power as probe early universe physics, consider cross-correlations with CMB temperature anisotropies. assess...
ABSTRACT Cosmic Dawn (CD) and Epoch of Reionization (EoR) are epochs the Universe which host invaluable information about cosmology astrophysics X-ray heating hydrogen reionization. Radio interferometric observations 21-cm line at high redshifts have potential to revolutionize our understanding during this time. However, modelling evolution these is particularly challenging due complex interplay many physical processes. This makes it difficult perform conventional statistical analysis using...
Fluctuations of the 21 cm brightness temperature before formation first stars hold promise becoming a high-precision cosmological probe in future. The growth overdensities is very well described by perturbation theory at that epoch, and signal can principle be predicted to arbitrary accuracy for given parameters. Recently, Tseliakhovich Hirata pointed out previously neglected important physical effect, due fact baryons cold dark matter (CDM) have supersonic relative velocities after...
It is generally expected that heavy fields are present during inflation, which can leave their imprint in late-time cosmological observables. The main signature of these a small amount distinctly shaped non-Gaussianity, if detected, would provide wealth information about the particle spectrum inflationary Universe. Here we investigate to what extent signatures be detected or constrained using futuristic 21-cm surveys. We construct model-independent templates extract squeezed-limit behavior...
In this first of two papers, we present a new method for searching oscillatory features in the primordial power spectrum. A wide variety models predict these one different flavors: logarithmically spaced oscillations and linearly oscillations. The proposed treats as perturbations on top scale-invariant spectrum, allowing us to vary all cosmological parameters. This perturbative approach reduces computational requirements search transfer functions their derivatives can be precomputed. We show...
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...
CMB-HD is a proposed millimeter-wave survey over half the sky that would be ultra-deep (0.5 uK-arcmin) and have unprecedented resolution (15 arcseconds at 150 GHz). Such answer many outstanding questions about fundamental physics of Universe. Major advances 1.) use gravitational lensing primordial microwave background to map distribution matter on small scales (k~10 h Mpc^(-1)), which probes dark particle properties. It will also allow 2.) measurements thermal kinetic Sunyaev-Zel'dovich...
We introduce and validate a delensing framework for the Simons Observatory (SO), which will be used to improve constraints on inflationary gravitational waves by reducing lensing noise in measurements of $B$ modes CMB polarization. SO initially observe using three small aperture telescopes one large-aperture telescope. While polarization maps from small-aperture constrain waves, internal delens reconstructed data Since obtained dominated subdegree scales, constructs template lensing-induced...
In the pursuit of primordial non-Gaussianities, we hope to access smaller scales across larger comoving volumes. At low redshift, search for non-Gaussianities is hindered by gravitational collapse, with which often associate a scale ${k}_{\mathrm{NL}}$. Beyond these scales, it will be hard reconstruct modes sensitive distribution. When forecasting future constraints on amplitude non-Gaussianity, ${f}_{\mathrm{NL}}$, off-diagonal components are usually neglected in covariance because they...
We detail the REACH radiometric system designed to enable measurements of 21-cm neutral hydrogen line. Included is radiometer architecture and end-to-end simulations as well a discussion challenges intrinsic highly-calibratable development. Following this, we share laboratory results based on calculation noise wave parameters utilising an over-constrained least squares approach. For five hours integration custom-made source with comparable impedance that antenna used in field, demonstrate...
We develop a machine learning approach to reconstructing the cosmological initial conditions from late-time dark matter halo number density fields in redshift space, with goal of improving sensitivity parameters, and particular primordial non-Gaussianity. Using an U-Net architecture, our model achieves cross-correlation accuracy 44% for scales out $k = 0.4 \text{ h}/\text{Mpc}$ between reconstructed true Quijote 1 Gpc$^3$ simulation boxes average $\bar{n} 4\times 10^{-4}$ (h/Mpc)$^{3}$...
We present the first attempt to use a combination of CMB, LIGO, and Pulsar Timing Array (PPTA) data constrain both tilt running primordial tensor power spectrum through constraints on gravitational wave energy density generated in early universe. Combining measurements at different cosmological scales highlights how complementary can be used test predictions universe models including inflationary consistency relation. Current prefer slightly positive...
We study the degree to which cosmic microwave background (CMB) can be used constrain primordial non-Gaussianity involving one tensor and two scalar fluctuations, focusing on correlation of polarization $B$ mode with temperature modes. In simplest models inflation, tensor-scalar-scalar bispectrum is nonvanishing same order in slow-roll parameters as scalar-scalar-scalar bispectrum. calculate $⟨BTT⟩$ arising from a bispectrum, show that constraints an experiment like CMB-Stage IV using this...