A5020874181- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Astronomy and Astrophysical Research
- Music Technology and Sound Studies
- Stellar, planetary, and galactic studies
- Astrophysics and Cosmic Phenomena
- Heavy Metal Exposure and Toxicity
- Heavy metals in environment
- Radio Astronomy Observations and Technology
- Oral Health Pathology and Treatment
- Data-Driven Disease Surveillance
- Power Line Communications and Noise
- Wireless Communication Networks Research
- Gamma-ray bursts and supernovae
- Environmental Justice and Health Disparities
- Chromium effects and bioremediation
- Occupational and environmental lung diseases
- Dark Matter and Cosmic Phenomena
- Scientific Research and Discoveries
- Head and Neck Cancer Studies
- Atomic and Subatomic Physics Research
- Arsenic contamination and mitigation
- Water Quality and Pollution Assessment
- Groundwater and Watershed Analysis
- Fluid Dynamics and Turbulent Flows
Brookhaven National Laboratory
2019-2020
Stony Brook University
2016-2019
Industrial Technology Research Institute
2014-2017
Max Planck Society
2015
Max Planck Institute for Astrophysics
2013-2015
ITRI International
2012
The University of Texas at Austin
2012
National Taiwan University
2010-2011
The influence of large-scale density fluctuations on structure formation small scales is described by the three-point correlation function (bispectrum) in so-called ``squeezed configurations,'' which one wavenumber, say k3, much smaller than other two, i.e., k3 << k1 ≈ k2. This bispectrum generated non-linear gravitational evolution and possibly also inflationary physics. In this paper, we use fact to show that squeezed configurations can be measured without employing estimators....
Abstract The large-scale statistics of observables such as the galaxy density are chiefly determined by their dependence on local coarse-grained matter density. This can be measured directly and efficiently in N-body simulations using fact that a uniform perturbation with respect to some fiducial background cosmology is equivalent modifying including curvature, i.e. simulating ‘separate universe’. We derive this mapping fully non-linear order, provide step-by-step description how perform...
In Taiwan many factors, whether geological parent materials, human activities, and climate change, can affect the groundwater quality its stability. This work combines factor analysis kriging with information entropy theory to interpret stability of variation in between 2005 2007. Groundwater demonstrated apparent differences northern southern areas when divided by Wu River. Approximately 52% monitoring wells suffered from progressing seawater intrusion, causing unstable quality. Industrial...
Galaxy proto-clusters at z >~ 2 provide a direct probe of the rapid mass assembly and galaxy growth present day massive clusters. Because need precise redshifts for density mapping prevalence star formation before quenching, nearly all known to date were confirmed by spectroscopy galaxies with strong emission lines. Therefore, large emission-line surveys an efficient way identify directly. Here we report discovery large-scale structure = 2.44 in HETDEX Pilot Survey. On scale few tens Mpc...
The Quijote simulations are a set of 44,100 full N-body spanning more than 7,000 cosmological models in the $\{\Omega_{\rm m}, \Omega_{\rm b}, h, n_s, \sigma_8, M_\nu, w \}$ hyperplane. At single redshift contain 8.5 trillions particles over combined volume $(h^{-1}{\rm Gpc})^3$; each simulation follow evolution $256^3$, $512^3$ or $1024^3$ box $1~h^{-1}{\rm Gpc}$ length. Billions dark matter halos and cosmic voids have been identified simulations, whose runs required 35 million core hours....
Abstract Background To explore if exposures to specific heavy metals in the environment is a new risk factor of oral cancer, one fastest growing malignancies Taiwan, addition two established factors, cigarette smoking and betel quid chewing. Methods This an observational study utilized age-standardized incidence rates cancer 316 townships precincts local prevalence chewing, demographic socio-economic conditions, concentrations farm soils eight kinds metal. Spatial regression GIS (Geographic...
Cosmic background neutrinos have a large velocity dispersion, which causes the evolution of long-wavelength density perturbations to depend on scale. This scale-dependent growth leads well-known suppression in linear theory matter power spectrum that is used probe neutrino mass. In this paper, we study impact small-scale structure formation. By performing separate universe simulations where mode absorbed into local expansion, measure responses cold dark (CDM) and halo mass function,...
Using $N$-body simulations with massive neutrino density perturbations, we detect the scale-dependent linear halo bias high significance. This is first time that this effect detected in containing perturbations on all scales, confirming same finding from separate universe simulations. The scale dependence result of additional system, i.e. free-streaming length, and it persists even if defined respect to cold dark matter plus baryon (instead total matter) power spectrum. approach provides a...
We show that in a certain, angle-averaged squeezed limit, the $N$-point function of matter is related to response power spectrum long-wavelength density perturbation, $P^{-1}d^nP(k|\delta_L)/d\delta_L^n|_{\delta_L=0}$, with $n=N-2$. By performing N-body simulations homogeneous overdensity superimposed on flat Friedmann-Robertson-Lema\^itre-Walker (FRLW) universe using \emph{separate universe} approach, we obtain measurements nonlinear up $n=3$, which equivalent measuring fully $3-$ $5-$point...
The acoustic peaks in the angular power spectrum of cosmic microwave background (CMB) temperature and polarization anisotropies play an important role as a probe nature new relativistic particles contributing to radiation density early universe, parametrized by Δ Neff. amplitude phase oscillations provide information about whether extra species are free-streaming particles, like neutrinos, or tightly-coupled, photons, during eras probed CMB. On other hand, some extensions Standard Model...
This study aimed to elucidate whether or not high-risk clusters of oral cancer (OC) incidence spatially correlate with the prevalence rates betel quid chewing (BQC) and cigarette smoking (CS) in Taiwan. The spatial autocorrelation potential OC among 307 townships heavy metal content soil throughout Taiwan were identified using Anselin's local Moran test. Additionally, correlations OC, BQC CS determined based on a comparison clusters. High-risk (Moran's I = 0.638, P <0.001) located central...
The separate universe technique provides a means of establishing consistency relations between short wavelength observables and the long matter density fluctuations within which they evolve by absorbing latter into cosmological background. We extend it to cases where non-gravitational forces introduce Jeans scale in other species like dynamical dark energy or massive neutrinos. matches synchronous gauge local expansion using acceleration equation accounts for temporal nonlocality dependence...
Central and Eastern Taiwan have alarmingly high oral cancer (OC) mortality rates, however, the effect of lifestyle factors such as betel chewing cannot fully explain observed high-risk. Elevated concentrations heavy metals in soil reflect somewhat levels exposure to human body, which may promote development local residents. This study assesses space-time distribution OC Taiwan, its association with prime leading metal content. The current research obtained data from Atlas Cancer Mortality...
We present a public code to generate mock galaxy catalog in redshift space assuming log-normal probability density function (PDF) of and matter fields. draw galaxies by Poisson-sampling the field, calculate velocity field from linearised continuity equation fields, zero vorticity. This procedure yields PDF pairwise fields that is qualitatively similar N-body simulations. check fidelity catalog, showing measured two-point correlation power spectrum real agree with input precisely. find linear...
We report on the first measurement of three-point function with position-dependent correlation from SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 10 CMASS sample. This new observable measures between two-point functions galaxy pairs within different subvolumes, (ř,řL), where řL is location a subvolume, and corresponding mean overdensities, (řL). correlation, which we call "integrated function", iζ(r)≡⟨(ř,řL)(řL)⟩, two short- one long-wavelength modes, generated by...
We report on the first measurement of three-point function with position-dependent correlation from SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 10 CMASS sample. This new observable measures between two-point functions galaxy pairs within different subvolumes, (ř,řL), where řL is location a subvolume, and corresponding mean overdensities, (řL). correlation, which we call "integrated function", iζ(r)≡⟨(ř,řL)(řL)⟩, two short- one long-wavelength modes, generated by...
Measurements of the Hubble parameter from distance ladder are in tension with indirect measurements based on cosmic microwave background (CMB) data and inverse at 3-4 $\sigma$ level. We consider phenomenological modification to timing width recombination process show that they can significantly affect this tension. This possibility is appealing, because such affects both last scattering surface calibration baryon acoustic oscillations (BAO) ruler. Moreover, only a very small fraction most...
The squeezed-limit bispectrum, which is generated by nonlinear gravitational evolution as well inflationary physics, measures the correlation of three wavenumbers, in configuration where one wavenumber much smaller than other two. Since bispectrum encodes impact a large-scale fluctuation on small-scale power spectrum, it can be understood how spectrum ``responds'' to fluctuation. Viewed this way, calculated using response approach even cases do not submit perturbative treatment. To...
By absorbing fluctuations into a local background, separate universe simulations provide powerful technique to characterize the response of small-scale observables long-wavelength density fluctuations, for example those power spectrum and halo mass function which lead squeezed-limit $n$-point bias, respectively. Using quintessence dark energy as paradigmatic example, we extend these simulation techniques cases where non-gravitational forces in other sectors establish Jeans scale across...
Survey observations of the three-dimensional locations galaxies are a powerful approach to measure distribution matter in universe, which can be used learn about nature dark energy, physics inflation, neutrino masses, etc. A competitive survey, however, requires large volume (e.g., Vsurvey is roughly 10 Gpc3) covered, and thus tends expensive. "sparse sampling" method offers more affordable solution this problem: within survey footprint covering given volume, Vsurvey, we observe only...
We present a new observable, position-dependent power spectrum, to measure the large-scale structure bispectrum in squeezed configuration, where one wavenumber is much smaller than other two. The squeezed-limit measures how small-scale spectrum modulated by long-wavelength overdensity, which due gravitational evolution and possibly inflationary physics. divide survey into small subvolumes, compute local mean overdensity each subvolume, correlation between them. integral of bispectrum,...