Daniel Green
A5100652438- Cosmology and Gravitation Theories
- Particle physics theoretical and experimental studies
- Black Holes and Theoretical Physics
- Dark Matter and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- High-Energy Particle Collisions Research
- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Quantum Chromodynamics and Particle Interactions
- Computational Physics and Python Applications
- Astronomy and Astrophysical Research
- Geophysics and Gravity Measurements
- Neutrino Physics Research
- Advanced Thermodynamics and Statistical Mechanics
- Relativity and Gravitational Theory
- Particle Detector Development and Performance
- Superconducting and THz Device Technology
- Solar and Space Plasma Dynamics
- Quantum Mechanics and Applications
- Superconducting Materials and Applications
- Stochastic processes and financial applications
- Noncommutative and Quantum Gravity Theories
- Adaptive optics and wavefront sensing
- Gamma-ray bursts and supernovae
- Meteorological Phenomena and Simulations
University of California, San Diego
2018-2024
Fermi National Accelerator Laboratory
1998-2024
Earth Island Institute
2023
Stanford University
2006-2022
University of Minnesota
2018-2022
Texas Scottish Rite Hospital for Children
2022
Scottish Rite Hospital
2022
Hospital for Special Surgery
2022
Naval Postgraduate School
2021
University of California, Berkeley
2016-2018
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.
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...
Supersymmetry plays a fundamental role in the radiative stability of many inflationary models. Spontaneous breaking symmetry inevitably leads to fields with masses order Hubble scale during inflation. When these couple inflaton, they produce unique signature squeezed limit three-point function primordial curvature perturbations. In this paper, we make connection between naturalness, supersymmetry, Hubble-mass degrees freedom, and precise. To study physics model-insensitive way, develop...
Large scale structure surveys promise to be the next leading probe of cosmological information. It is therefore crucial reliably predict their observables. The Effective Field Theory Scale Structures (EFTofLSS) provides a manifestly convergent perturbation theory for weakly non-linear regime dark matter, where correlation functions are computed in an expansion wavenumber k mode over associated with k_nl. Since most information contained at high wavenumbers, it necessary compute higher order...
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...
This white paper summarizes recent progress in the cosmologicalbootstrap, an approach to study of statistics primordialfluctuations from consistency with unitarity, locality and symmetryassumptions. We review key ideas bootstrap method, aneye towards future directions ambitions program. Focusing onrecent involving de Sitter quasi-de backgrounds, wehighlight role singularities unitarity constraining theform correlators. also discuss nonperturbative formulations ofthe bootstrap, connections...
A bstract The baryon acoustic oscillation (BAO) analysis from the first year of data Dark Energy Spectroscopic Instrument (DESI), when combined with cosmic microwave background (CMB), has placed an upper-limit on sum neutrino masses, ∑ m ν < 70 meV (95%). In addition to excluding minimum associated inverted hierarchy, posterior is peaked at = 0 and close even minumum sum, 58 2 σ . this paper, we explore implications for cosmology particle physics. mass determined in suppression clustering...
Soft limits of inflationary correlation functions are both observationally relevant and theoretically robust. Various theorems can be proven about them that insensitive to detailed model-building assumptions. In this paper, we re-derive several these in a universal way. Our method makes manifest why soft such an interesting probe the spectrum additional light fields during inflation. We illustrate abstract results with case study quasi-single-field
Fluctuations in the cosmic neutrino background are known to produce a phase shift acoustic peaks of microwave background. It is through sensitivity this effect that recent CMB data has provided robust detection free-streaming neutrinos. In paper, we revisit anisotropy spectrum as probe new physics. The particularly interesting because its physical origin strongly constrained by analytic properties Green's function gravitational potential. For adiabatic fluctuations, requires modes propagate...
Future cosmic microwave background experiments have the potential to probe density of relativistic species at subpercent level. This sensitivity allows light thermal relics be detected up arbitrarily high decoupling temperatures. Conversely, absence a detection would require extra never been in equilibrium with Standard Model. In this Letter, we exploit feature demonstrate future cosmological observations couplings axions photons, gluons, and charged fermions. many cases, constraints...
We examine the effective theory of single-field inflation in limit where scalar perturbations propagate with a small speed sound. In this case non-linearly realized time-translation symmetry Lagrangian implies large interactions, giving rise to primordial non-Gaussianities. When non-Gaussianities are measurable, these interactions will become strongly coupled unless new physics appears close Hubble scale. Due its proximity scale, is not necessarily decoupled from inflationary observables and...
Large scale structure surveys are likely the next leading probe of cosmological information. It is therefore crucial to reliably predict their observables. The Effective Field Theory Scale Structures (EFTofLSS) provides a manifestly convergent perturbation theory for weakly non-linear regime, where dark matter correlation functions computed in an expansion wavenumber k over associated kNL. To push predictions higher wavenumbers, it necessary compute 2-loop power spectrum. For equal-time...
The analyticity of response functions and scattering amplitudes implies powerful relations between low-energy observables the underlying short-distance dynamics. These ``IR/UV'' are rooted in basic physical principles, such as causality unitarity. In this paper, we seek similar connections inflation, relating cosmological observations to physics responsible for accelerated expansion. We assume that inflationary theory is Lorentz invariant at short distances, but allow nonrelativistic...
This paper provides a systematic study of renormalization in models halo biasing. Building on work McDonald, we show that Eulerian biasing is only consistent with if non-local terms and higher-derivative contributions are included the model. We explicitly determine complete list required bias parameters for Gaussian initial conditions, up to quartic order dark matter density contrast at leading derivatives. At quadratic order, this means including gravitational tidal tensor, while cubic...
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...
A bstract Calculating the quantum evolution of a de Sitter universe on superhorizon scales is notoriously difficult. To address this challenge, we introduce Soft Effective Theory (SdSET). This framework holds for modes whose comoving momentum far below UV scale, which set by inverse horizon. The SdSET formulated using same approach that yields Heavy Quark Theory. degrees freedom capture long wavelength dynamics are identified with growing and decaying solutions to equations motion. operator...
Structure in the Universe is widely believed to have originated from quantum fluctuations during an early epoch of accelerated expansion. Yet, patterns we observe today do not distinguish between or classical primordial fluctuations; current cosmological data are consistent with either possibility. We argue here that a detection non-Gaussianity can resolve present situation, and provide litmus test for origin cosmic structure. Unlike mechanics, vacuum cannot arise theories therefore...
Abstract The effects of gravitational lensing the cosmic microwave background (CMB) have been measured at high significance with existing data and will be even more precisely in future surveys. Reversing on observed CMB temperature polarization maps provides a variety benefits. Delensed spectra sharper acoustic peaks prominent damping tails, allowing for improved inferences cosmological parameters that impact those features. Delensing reduces B -mode power, aiding search primordial waves...
A bstract Effective field theories in flat space and anti-de Sitter are constrained by causality unitarity, often the form of positivity bounds. Similar bounds have been harder to demonstrate cosmological backgrounds, where roles unitarity more obscure. Fortunately, expansion universe ensures that late-time correlators effectively classical role is played statistical inequalities. For multi-field inflation, resulting constraints long known terms Suyama-Yamaguchi inequality. In this paper, we...
Abstract Primordial non-Gaussianity generated by additional fields present during inflation offers a compelling observational target for galaxy surveys. These are of significant theoretical interest since they offer window into particle physics in the inflaton sector. They also violate single-field consistency conditions and induce scale-dependent bias power spectrum. In this paper, we explore particular signal light scalar study prospects measuring it with We find that sensitivities current...