More than 40% of children develop caries in primary dentition by 6 years of age, and more than 85... more More than 40% of children develop caries in primary dentition by 6 years of age, and more than 85% develop caries in the permanent dentition by age 17 (Kaste et al. 1996). Despite a reduction in the prevalence of caries in the permanent dentition, the prevalence in the primary ...
We present a set of ultra-large particle-mesh simulations of the Lyα forest targeted at understan... more We present a set of ultra-large particle-mesh simulations of the Lyα forest targeted at understanding the imprint of baryon acoustic oscillations in the inter-galactic medium. We use nine dark matter only simulations which can, for the first time, simultaneously resolve the Jeans scale of the intergalactic gas while covering the large volumes required to adequately sample the acoustic feature. Mock absorption spectra are generated using the fluctuating Gunn-Peterson approximation which have approximately correct flux probability density functions and small-scale power spectra. On larger scales, there is clear evidence in the redshift-space correlation function for an acoustic feature, which matches a linear theory template with constant bias. These spectra, which we make publicly available, can be used to test pipelines, plan future experiments, and model various physical effects. As an illustration, we discuss the basic properties of the acoustic signal in the forest, the scaling of errors with noise and source number density, modified statistics to treat mean flux evolution and mis-estimation, and non-gravitational sources such as fluctuations in the photoionizing background and temperature fluctuations due to He II reionization.
We present a set of ultra-large particle-mesh simulations of the Lyα forest targeted at understan... more We present a set of ultra-large particle-mesh simulations of the Lyα forest targeted at understanding the imprint of baryon acoustic oscillations in the inter-galactic medium. We use nine dark matter only simulations which can, for the first time, simultaneously resolve ...
... Salman Habib, Adrian Pope, Zarija Lukic, David Daniel, Patricia Fasel, Nehal Desai, Katrin He... more ... Salman Habib, Adrian Pope, Zarija Lukic, David Daniel, Patricia Fasel, Nehal Desai, Katrin Heitmann, Chung-Hsing Hsu, Lee Ankeny, Graham Mark, Suman Bhattacharya and James Ahrens Los Alamos National Laboratory, Los Alamos, New Mexico, NM 87545 E-mail: habib ...
ABSTRACT Large-volume sky surveys have accessed the Universe's vast temporal and spatial ... more ABSTRACT Large-volume sky surveys have accessed the Universe's vast temporal and spatial expanse via a remarkable set of measurements, and many more are sure to follow. To make new predictions for these cosmological observations and to properly interpret them, large-scale numerical simulation and modeling has become an essential tool. Here, the authors discuss Hardware/Hybrid Accelerated Cosmology Code (HACC), an extreme-scale N-body cosmology code and its associated analysis framework, focusing on the complexity of the analysis workflow, which is as important as running the underlying simulation.
More than 40% of children develop caries in primary dentition by 6 years of age, and more than 85... more More than 40% of children develop caries in primary dentition by 6 years of age, and more than 85% develop caries in the permanent dentition by age 17 (Kaste et al. 1996). Despite a reduction in the prevalence of caries in the permanent dentition, the prevalence in the primary ...
We present a set of ultra-large particle-mesh simulations of the Lyα forest targeted at understan... more We present a set of ultra-large particle-mesh simulations of the Lyα forest targeted at understanding the imprint of baryon acoustic oscillations in the inter-galactic medium. We use nine dark matter only simulations which can, for the first time, simultaneously resolve the Jeans scale of the intergalactic gas while covering the large volumes required to adequately sample the acoustic feature. Mock absorption spectra are generated using the fluctuating Gunn-Peterson approximation which have approximately correct flux probability density functions and small-scale power spectra. On larger scales, there is clear evidence in the redshift-space correlation function for an acoustic feature, which matches a linear theory template with constant bias. These spectra, which we make publicly available, can be used to test pipelines, plan future experiments, and model various physical effects. As an illustration, we discuss the basic properties of the acoustic signal in the forest, the scaling of errors with noise and source number density, modified statistics to treat mean flux evolution and mis-estimation, and non-gravitational sources such as fluctuations in the photoionizing background and temperature fluctuations due to He II reionization.
We present a set of ultra-large particle-mesh simulations of the Lyα forest targeted at understan... more We present a set of ultra-large particle-mesh simulations of the Lyα forest targeted at understanding the imprint of baryon acoustic oscillations in the inter-galactic medium. We use nine dark matter only simulations which can, for the first time, simultaneously resolve ...
... Salman Habib, Adrian Pope, Zarija Lukic, David Daniel, Patricia Fasel, Nehal Desai, Katrin He... more ... Salman Habib, Adrian Pope, Zarija Lukic, David Daniel, Patricia Fasel, Nehal Desai, Katrin Heitmann, Chung-Hsing Hsu, Lee Ankeny, Graham Mark, Suman Bhattacharya and James Ahrens Los Alamos National Laboratory, Los Alamos, New Mexico, NM 87545 E-mail: habib ...
ABSTRACT Large-volume sky surveys have accessed the Universe's vast temporal and spatial ... more ABSTRACT Large-volume sky surveys have accessed the Universe's vast temporal and spatial expanse via a remarkable set of measurements, and many more are sure to follow. To make new predictions for these cosmological observations and to properly interpret them, large-scale numerical simulation and modeling has become an essential tool. Here, the authors discuss Hardware/Hybrid Accelerated Cosmology Code (HACC), an extreme-scale N-body cosmology code and its associated analysis framework, focusing on the complexity of the analysis workflow, which is as important as running the underlying simulation.
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Papers by David Daniel