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233
2hot: An improved parallel hashed octtree nbody algorithm for cosmological simulation
 in Proceedings of SC13: International Conference for High Performance Computing, Networking, Storage and Analysis, SC ’13
, 2013
"... We report on improvements made over the past two decades to our adaptive treecode Nbody method (HOT). A mathematical and computational approach to the cosmological Nbody problem is described, with performance and scalability measured up to 256k (218) processors. We present error analysis and sci ..."
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Cited by 3 (1 self)
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We report on improvements made over the past two decades to our adaptive treecode Nbody method (HOT). A mathematical and computational approach to the cosmological Nbody problem is described, with performance and scalability measured up to 256k (218) processors. We present error analysis
GALAXIES IN NBODY SIMULATIONS: OVERCOMING THE OVERMERGING PROBLEM
, 1997
"... A significant fraction of mass of galaxies is provided by the dark matter. To some extent galaxies are large dense halos of the dark matter. However, dissipationless cosmological Nbody simulations have been consistently failing to produce galaxysize dark matter halos in dense environments typical ..."
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Cited by 5 (1 self)
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A significant fraction of mass of galaxies is provided by the dark matter. To some extent galaxies are large dense halos of the dark matter. However, dissipationless cosmological Nbody simulations have been consistently failing to produce galaxysize dark matter halos in dense environments typical
R.N.: Modeling and Simulation of Scalable Cloud Computing Environments and the CloudSim Toolkit: Challenges and Opportunities, Keynote Paper
 In: Proceedings of the 7th High Performance Computing and Simulation (HPCS 2009) Conference
, 2009
"... Cloud computing aims to power the next generation data centers and enables application service providers to lease data center capabilities for deploying applications depending on user QoS (Quality of Service) requirements. Cloud applications have different composition, configuration, and deployment ..."
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Cited by 115 (18 self)
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challenging problem to tackle. To simplify this process, in this paper we propose CloudSim: an extensible simulation toolkit that enables modelling and simulation of Cloud computing environments. The CloudSim toolkit supports modelling and creation of one or more virtual machines (VMs) on a simulated node
COSMOLOGICAL MODELS OF MODIFIED GRAVITY
, 2013
"... The recent discovery of dark energy has prompted an investigation of ways in which the accelerated expansion of the universe can be realized. In this dissertation, we present two separate projects related to dark energy. The first project analyzes a class of braneworld models in which multiple brane ..."
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energy description can be obtained for braneworld scenarios, allowing for a number of generalizations to the original models. This method is applied to orbifolded and uncompactified Nbrane models, deriving an effective fourdimensional action. The parameter space of this theory is constrained using observational
Preprint typeset using L ATEX style emulateapj v. 11/26/04 INITIAL CONDITIONS TO COSMOLOGICAL NBODY SIMULATIONS, OR HOW TO RUN AN ENSEMBLE OF SIMULATIONS
, 2008
"... The conventional method of generating initial conditions for cosmological Nbody simulations introduces a significant error in the realspace statistical properties of the particles. More specifically, the finite box size leads to a significant underestimate of σ8, the correlation function, and nonl ..."
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The conventional method of generating initial conditions for cosmological Nbody simulations introduces a significant error in the realspace statistical properties of the particles. More specifically, the finite box size leads to a significant underestimate of σ8, the correlation function
Sources of contamination to weak lensing threepoint statistics: constraints from Nbody simulations
, 2008
"... We investigate the impact of the observed correlation between a galaxies shape and its surrounding density field on the measurement of third order weak lensing shear statistics. Using numerical simulations, we estimate the systematic error contribution to a measurement of the third order moment of t ..."
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Cited by 1 (0 self)
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to be an order of magnitude larger than the expected cosmological GGG shear signal. Compared to the twopoint intrinsic ellipticity correlation which is similar in amplitude to the twopoint shear signal at these survey depths, third order statistics therefore offer a promising new way to constrain models
Numerical action reconstruction of the dynamical history of dark matter haloes in Nbody simulations
, 2008
"... We test the ability of the numerical action method (NAM) to recover the individual orbit histories of mass tracers in an expanding universe in a region of radius 26 h −1 Mpc, given the masses and redshiftspace coordinates at the present epoch. The mass tracers are represented by dark matter haloes ..."
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identified in a high resolution Nbody simulation of the standard ΛCDM cosmology. Since previous tests of NAM at this scale have traced the underlying distribution of dark matter particles rather than extended haloes, our study offers an assessment of the accuracy of NAM in a scenario which more closely
A scalable and nearly uniform generator of SAT witnesses
 In Proc. of CAV
, 2013
"... Abstract. Functional verification constitutes one of the most challenging tasks in the development of modern hardware systems, and simulationbased verification techniques dominate the functional verification landscape. A dominant paradigm in simulationbased verification is directed random testing, ..."
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Cited by 13 (6 self)
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, where a model of the system is simulated with a set of random test stimuli that are uniformly or nearuniformly distributed over the space of all stimuli satisfying a given set of constraints. Uniform or nearuniform generation of solutions for large constraint sets is therefore a problem of theoretical
Scalable DistributiontoDistribution Regression
, 2014
"... In this thesis I present a scalable approach to distributiontodistribution regression on large, multidimensional datasets. The basic algorithm is demonstrated on 1dimensional toy data, then modified for efficiency and scalability. Key enhancements include parallel computation of nonparametric ..."
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parametric estimators and the use of a ball tree to support efficient nearestneighbor search in high dimension. I then explore the ability of this technique to compute the final states of cosmological Nbody simulations. An existing method uses cosmological perturbation theory to rapidly approximate
Astrophysical Journal, in press Preprint typeset using L ATEX style emulateapj v. 04/03/99 GALAXIES IN NBODY SIMULATIONS: OVERCOMING THE OVERMERGING PROBLEM
, 1998
"... Astrophysical Journal, in press We present analysis of the evolution of dark matter halos in dense environments of groups and clusters in dissipationless cosmological simulations. The premature destruction of halos in such environments, known as the overmerging, reduces the predictive power of Nbod ..."
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Astrophysical Journal, in press We present analysis of the evolution of dark matter halos in dense environments of groups and clusters in dissipationless cosmological simulations. The premature destruction of halos in such environments, known as the overmerging, reduces the predictive power of Nbody
Results 1  10
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233