The Experts below are selected from a list of 3387 Experts worldwide ranked by ideXlab platform
Benjamin D. Wandelt - One of the best experts on this subject based on the ideXlab platform.
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Pico: Parameters for the Impatient Cosmologist
The Astrophysical Journal, 2007Co-Authors: William A. Fendt, Benjamin D. WandeltAbstract:We present a fast, accurate, robust, and flexible method of accelerating parameter estimation. This algorithm, called Pico, can compute the CMB power spectrum and matter transfer function, as well as any computationally expensive likelihoods, in a few milliseconds. By removing these bottlenecks from parameter estimation codes, Pico decreases their computational time by 1 or 2 orders of magnitude. Pico has several important properties. First, it is extremely fast and accurate over a large volume of parameter space. Furthermore, its accuracy can continue to be improved by using a larger training set. This method is generalizable to an arbitrary number of cosmological parameters and to any range of l-values in multipole space. Pico is approximately 3000 times faster than CAMB for flat models, and approximately 2000 times faster than the WMAP 3 yr likelihood code. In this paper, we demonstrate that using Pico to compute power spectra and likelihoods produces parameter posteriors that are very similar to those using CAMB and the official WMAP3 code, but in only a fraction of the time. Pico and an interface to CosmoMC are made publicly available on the authors' Web site at http://www.astro.uiuc.edu/~bwandelt/pico/.
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pico parameters for the impatient Cosmologist
arXiv: Astrophysics, 2006Co-Authors: William A. Fendt, Benjamin D. WandeltAbstract:We present a fast, accurate, robust and flexible method of accelerating parameter estimation. This algorithm, called Pico, can compute the CMB power spectrum and matter transfer function as well as any computationally expensive likelihoods in a few milliseconds. By removing these bottlenecks from parameter estimation codes, Pico decreases their computational time by 1 or 2 orders of magnitude. Pico has several important properties. First, it is extremely fast and accurate over a large volume of parameter space. Furthermore, its accuracy can continue to be improved by using a larger training set. This method is generalizable to an arbitrary number of cosmological parameters and to any range of l-values in multipole space. Pico is approximately 3000 times faster than CAMB for flat models, and approximately 2000 times faster then the WMAP 3 year likelihood code. In this paper, we demonstrate that using Pico to compute power spectra and likelihoods produces parameter posteriors that are very similar to those using CAMB and the official WMAP3 code, but in only a fraction of the time. Pico and an interface to CosmoMC are made publicly available at this http URL
William A. Fendt - One of the best experts on this subject based on the ideXlab platform.
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Pico: Parameters for the Impatient Cosmologist
The Astrophysical Journal, 2007Co-Authors: William A. Fendt, Benjamin D. WandeltAbstract:We present a fast, accurate, robust, and flexible method of accelerating parameter estimation. This algorithm, called Pico, can compute the CMB power spectrum and matter transfer function, as well as any computationally expensive likelihoods, in a few milliseconds. By removing these bottlenecks from parameter estimation codes, Pico decreases their computational time by 1 or 2 orders of magnitude. Pico has several important properties. First, it is extremely fast and accurate over a large volume of parameter space. Furthermore, its accuracy can continue to be improved by using a larger training set. This method is generalizable to an arbitrary number of cosmological parameters and to any range of l-values in multipole space. Pico is approximately 3000 times faster than CAMB for flat models, and approximately 2000 times faster than the WMAP 3 yr likelihood code. In this paper, we demonstrate that using Pico to compute power spectra and likelihoods produces parameter posteriors that are very similar to those using CAMB and the official WMAP3 code, but in only a fraction of the time. Pico and an interface to CosmoMC are made publicly available on the authors' Web site at http://www.astro.uiuc.edu/~bwandelt/pico/.
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pico parameters for the impatient Cosmologist
arXiv: Astrophysics, 2006Co-Authors: William A. Fendt, Benjamin D. WandeltAbstract:We present a fast, accurate, robust and flexible method of accelerating parameter estimation. This algorithm, called Pico, can compute the CMB power spectrum and matter transfer function as well as any computationally expensive likelihoods in a few milliseconds. By removing these bottlenecks from parameter estimation codes, Pico decreases their computational time by 1 or 2 orders of magnitude. Pico has several important properties. First, it is extremely fast and accurate over a large volume of parameter space. Furthermore, its accuracy can continue to be improved by using a larger training set. This method is generalizable to an arbitrary number of cosmological parameters and to any range of l-values in multipole space. Pico is approximately 3000 times faster than CAMB for flat models, and approximately 2000 times faster then the WMAP 3 year likelihood code. In this paper, we demonstrate that using Pico to compute power spectra and likelihoods produces parameter posteriors that are very similar to those using CAMB and the official WMAP3 code, but in only a fraction of the time. Pico and an interface to CosmoMC are made publicly available at this http URL
Hilmar Duerbeck - One of the best experts on this subject based on the ideXlab platform.
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Carl Wirtz — An early observational Cosmologist
Lecture Notes in Physics, 1Co-Authors: Hilmar DuerbeckAbstract:A brief sketch of Wirtz's contributions in cosmology and extragalactic research is given: the velocity — distance relation, the galaxy luminosity function, galaxy photometry, segregation in clusters, and intergalactic extinction.
James F. Lynch - One of the best experts on this subject based on the ideXlab platform.
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michael buckingham Cosmologist
Journal of the Acoustical Society of America, 2019Co-Authors: James F. LynchAbstract:Before Mike Buckingham became and ocean acoustician, he had a rather different career path—that of a Cosmologist trying to detect gravitational waves. In the late 1960s, physicist Joseph Weber published a paper in which he claimed to have measured Einstein’s gravitational waves. Efforts quickly ensued to either confirm or disprove Weber’s stunning claim—and Mike Buckingham was in the thick of these efforts. The story of Mike’s involvement traces a very interesting episode in the history of gravitational wave research. It also involves a fair bit of acoustics, as that was the technique used at that time (and is still pursued to some extent today). Perhaps most happily, this story explains how and why Mike Buckingham became an ocean acoustician, which is the ASA’s gain (though cosmology’s loss.)
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Michael Buckingham—Cosmologist
The Journal of the Acoustical Society of America, 2019Co-Authors: James F. LynchAbstract:Before Mike Buckingham became and ocean acoustician, he had a rather different career path—that of a Cosmologist trying to detect gravitational waves. In the late 1960s, physicist Joseph Weber published a paper in which he claimed to have measured Einstein’s gravitational waves. Efforts quickly ensued to either confirm or disprove Weber’s stunning claim—and Mike Buckingham was in the thick of these efforts. The story of Mike’s involvement traces a very interesting episode in the history of gravitational wave research. It also involves a fair bit of acoustics, as that was the technique used at that time (and is still pursued to some extent today). Perhaps most happily, this story explains how and why Mike Buckingham became an ocean acoustician, which is the ASA’s gain (though cosmology’s loss.)
Geoff Brumfiel - One of the best experts on this subject based on the ideXlab platform.
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Our Universe: outrageous fortune.
Nature, 2006Co-Authors: Geoff BrumfielAbstract:A growing number of Cosmologists and string theorists suspect the form of our Universe is little more than a coincidence. Are these harmless thought experiments, or a challenge to science itself? Geoff Brumfiel investigates.
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Focus: A Cosmic Yardstick
Physics, 2001Co-Authors: Geoff BrumfielAbstract:A set of just three parameters will allow Cosmologists to compare all of their dark energy theories with the data.
