A5081628831- Nuclear physics research studies
- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Nuclear Physics and Applications
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Advanced Chemical Physics Studies
- Astronomical and nuclear sciences
- Atomic and Molecular Physics
- Computational Physics and Python Applications
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Scientific Research and Discoveries
- Neutrino Physics Research
- Nuclear reactor physics and engineering
- Geophysics and Gravity Measurements
- Radiation Detection and Scintillator Technologies
- Statistical and numerical algorithms
- Astrophysics and Star Formation Studies
- Radiopharmaceutical Chemistry and Applications
- Dark Matter and Cosmic Phenomena
- Advanced Electrical Measurement Techniques
- High voltage insulation and dielectric phenomena
- Radio Astronomy Observations and Technology
- Advanced Data Compression Techniques
Max Planck Institute for Astrophysics
2022-2024
Stony Brook University
2019-2023
Flatiron Health (United States)
2023
Flatiron Institute
2023
University of Guelph
2012-2019
University of Toronto
2016
Primordial non-Gaussianity (PNG) is one of the most powerful probes early Universe and measurements large scale structure have potential to transform our understanding this area. However relating late time primordial perturbations challenging due non-linear processes that govern evolution Universe. To help address issue we release a suite N-body simulations containing four types PNG: \textsc{quijote-png}. These were designed augment \textsc{quijote} explored impact various cosmological...
Abstract We investigate how much can be learnt about four types of primordial non-Gaussianity (PNG) from small-scale measurements the halo field. Using quijote-png simulations, we quantify information content accessible with power spectrum monopole and quadrupole, matter spectrum, halo–matter cross bispectrum monopole. This analysis is first to include small, nonlinear scales, up <?CDATA ${k}_{\max }=0.5\,{\rm{h}}\,{\mathrm{Mpc}}^{-1}$?> <mml:math...
Abstract Rapid advances in deep learning have brought not only a myriad of powerful neural networks, but also breakthroughs that benefit established scientific research. In particular, automatic differentiation (AD) tools and computational accelerators like GPUs facilitated forward modeling the Universe with differentiable simulations. Based on analytic or backpropagation, current cosmological simulations are limited by memory, thus subject to trade-off between time space/mass resolution,...
Abstract We build a field-level emulator for cosmic structure formation that is accurate in the nonlinear regime. Our consists of two convolutional neural networks trained to output displacements and velocities N -body simulation particles based on their linear inputs. Cosmology dependence encoded form style parameters at each layer network, enabling effectively interpolate outcomes between different flat Lambda cold dark matter cosmologies over wide range background densities. The network...
ABSTRACT Recently, hybrid bias expansions have emerged as a powerful approach to modelling the way in which galaxies are distributed Universe. Similarly, field-level emulators recently become possible, thanks advances machine learning and N-body simulations. In this paper, we explore whether both techniques can be combined provide model for clustering of real redshift space. Specifically, here will demonstrate that able accurately predict all operators second-order expansion. The precision...
Abstract The Effective Field Theory of Large Scale Structure (EFTofLSS) has found tremendous success as a perturbative framework for the evolution large scale structure, and it is now routinely used to compare theoretical predictions against cosmological observations. model total matter field includes one nuisance parameter at 1-loop order, effective sound speed, which can be extracted by matching EFT full N-body simulations. In this work we first leverage Layzer-Irvine cosmic energy...
We apply and test a field-level emulator for non-linear cosmic structure formation in volume matching next-generation surveys. Inferring the cosmological parameters initial conditions from which particular galaxy distribution of our Universe was seeded can be achieved by comparing simulated data to observational data. Previous work has focused on building accelerated forward models that efficiently mimic these simulations. One uses machine learning correction linear $z=0$ Zeldovich...
Abstract We present a field-level emulator for large-scale structure, capturing the cosmology dependence and time evolution of cosmic structure formation. The maps linear displacement fields to their corresponding nonlinear displacements from N-body simulations at specific redshifts. Designed as neural network, incorporates style parameters that encode dependencies on Ω m growth factor D ( z ) redshift . train our model six-dimensional phase space, predicting particle velocities derivative...
The statistics of thermal gas pressure are a new and promising probe cosmology astrophysics. large-scale cross-correlation between galaxies the Sunyaev-Zeldovich effect gives bias-weighted mean electron pressure, <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mo stretchy="false">⟨</a:mo><a:msub><a:mi>b</a:mi><a:mi mathvariant="normal">h</a:mi></a:msub><a:msub><a:mi>P</a:mi><a:mi>e</a:mi></a:msub><a:mo stretchy="false">⟩</a:mo></a:math>. In this paper, we show that...
ABSTRACT We introduce the parity-odd power (POP) spectra, a novel set of observables for probing parity violation in cosmological N-point statistics. POP spectra are derived from composite fields obtained by applying non-linear transformations, involving also gradients, curls, and filtering functions, to scalar field. This compresses trispectrum into spectrum. These new statistics offer several advantages: they computationally fast construct, estimating their covariance is less demanding...
Future Large Scale Structure surveys are expected to improve over current bounds on primordial non-Gaussianity (PNG), with a significant impact our understanding of early Universe physics. The level such improvements will however strongly depend the extent which late time non-linearities erase PNG signal small scales. In this work, we show how much information remains in bispectrum non-linear dark matter density field by implementing new, simulation-based, methodology for joint estimation...
Abstract We study signatures of primordial non-Gaussianity (PNG) in the redshift-space halo field on nonlinear scales using a combination three summary statistics, namely, mass function (HMF), power spectrum, and bispectrum. The choice adding HMF to our previous joint analysis spectrum bispectrum is driven by preliminary field-level analysis, which we train graph neural networks catalogs infer PNG f NL parameter. covariance matrix responses summaries changes model parameters are extracted...
We present a field-level emulator for large-scale structure, capturing the cosmology dependence and time evolution of cosmic structure formation. The maps linear displacement fields to their corresponding nonlinear displacements from N-body simulations at specific redshifts. Designed as neural network, incorporates style parameters that encode dependencies on $\Omega_{\rm m}$ growth factor $D(z)$ redshift $z$. train our model six-dimensional phase space, predicting particle velocities...
The half-life of the superallowed Fermi ${\ensuremath{\beta}}^{+}$ emitter ${}^{14}$O has been determined via simultaneous direct $\ensuremath{\beta}$ and $\ensuremath{\gamma}$ counting experiments at TRIUMF's Isotope Separator Accelerator (ISAC) facility. A $\ensuremath{\gamma}$-ray measurement was performed by detecting 2312.6-keV rays emitted from an excited state daughter ${}^{14}$N following implantation samples center 8$\ensuremath{\pi}$ spectrometer, a spherical array 20 high-purity...
The levels in 26Na with single particle character have been observed for the first time using d(25Na,p gamma) reaction at 5 MeV/nucleon. measured excitation energies and deduced spectroscopic factors are good overall agreement (0+1) hbar-omega shell model calculations performed a complete spsdfp basis incorporating reduction N=20 gap. Notably, 1p3/2 neutron configuration was found to play an enhanced role structure of low-lying negative parity states 26Na, compared isotone 28Al. Thus,...
We introduce the position-dependent probability distribution function (PDF) of smoothed matter field as a cosmological observable. In comparison to PDF itself, spatial variation is simpler model and has distinct dependence on parameters. demonstrate that characterized by variations in local mean density, we compute linear response density using separate universe N-body simulations. The can be thought bias regions selected based density. provide for response, which accurately predicts our...
The formation of the large-scale structure, evolution and distribution galaxies, quasars, dark matter on cosmological scales, requires numerical simulations. Differentiable simulations provide gradients parameters, that can accelerate extraction physical information from statistical analyses observational data. deep learning revolution has brought not only myriad powerful neural networks, but also breakthroughs including automatic differentiation (AD) tools computational accelerators like...
Precision measurements of superallowed Fermi β-decay transitions, particularly for the lightest emitters C10 and O14, set stringent limits on possible scalar current contributions to weak interaction. In present work, a discrepancy between recent half-life is addressed through two high-precision measurements, via γ-ray photopeak β counting, that yield consistent results T1/2=19.2969±0.0074 s T1/2=19.3009±0.0017 s, respectively. The latter most precise measurement reported date first achieve...
Abstract We study primordial non-Gaussian signatures in the redshift-space halo field on nonlinear scales, using a quasi-maximum likelihood estimator based optimally compressed power spectrum and modal bispectrum statistics. train validate suite of catalogs constructed from Quijote-png N -body simulations, which we release to accompany this paper. verify its unbiasedness near-optimality for three main types non-Gaussianity (PNG): local, equilateral, orthogonal. compare expansion with k...
Measurements of the galaxy 4-Point Correlation Function (4PCF) from theSloan Digital Sky Survey Baryon Oscillation Spectroscopic (SDSS BOSS) have recently found strong statistical evidence for parity violation. If this signal is genuine physical origin, it must stem beyond-Standard Model physics, most likely during very early Universe, prior to decoupling ($z$$\sim$$1,020$). Since Acoustic (BAO) features imprint at decoupling, they are expected in parity-odd 4PCF, and so detecting them would...
The half-life of the superallowed Fermi ${\ensuremath{\beta}}^{+}$ emitter $^{18}\mathrm{Ne}$ has been determined via two high-precision $\ensuremath{\beta}$ counting experiments at TRIUMF's Isotope Separator and Accelerator facility. Using different $4\ensuremath{\pi}$ continuous-flow gas-proportional counters, independent measurements were made, yielding a weighted average ${T}_{1/2}=1.{66400}_{\ensuremath{-}0.00048}^{+0.00057}$ s, which is consistent with but approximately 2 times more...
Voids have emerged as a novel probe of cosmology and large-scale structure. These regions extreme underdensity are sensitive to physics beyond the standard model cosmology, can potentially be used testing ground constrain new physics. We present first determination linear void bias measured in separate universe simulations. Our methods validated by comparing response with clustering voids. find excellent agreement between two for voids identified halo field down-sampled dark matter field....
A search for excited ${0}^{+}$ states in ${}^{62}$Zn was conducted via the ${}^{64}$Zn($p,t$)${}^{62}$Zn reaction. Four such were observed up to an excitation energy of 5.4 MeV. The measured angular distribution previously assigned ${0}_{2}^{+}$ state at 2342 keV is consistent with a ${2}^{+}$ assignment, and thus first now 3043 keV. Due scaling currently adopted formalism isospin-mixing corrections superallowed Fermi $\ensuremath{\beta}$ decay, ${\ensuremath{\delta}}_{C1}$ ${}^{62}$Ga...
States in $^{112}\mathrm{Cd}$ have been studied with the $^{111}\mathrm{Cd}(\stackrel{P\vec}{d},p)^{12}\mathrm{Cd}$ reaction using 22 MeV polarized deuterons. The protons from were momentum analyzed a Q3D magnetic spectrograph, and spectra recorded position-sensitive detector located on focal plane. Angular distributions of cross sections analyzing powers constructed for low-lying negative-parity states observed, including...
In a universe with quintessence isocurvature, or perturbations in dark energy that are independent from the usual curvature perturbations, structure formation is changed qualitatively. The existence of two fields, and causes growth rate matter to depend on their initial conditions. cause scale. We perform first separate simulations for this cosmology. demonstrate power spectrum response halo bias scale conditions presence isocurvature mode changes mapping these quantities auto- cross-power...