June 27, 2008 Scott Dodelson 1

Numerical Cosmology

Argonne-Fermilab-University of Chicago Collaboration

Meeting

June 27, 2008 Scott Dodelson 2

Need Simulations to Extract Science from Surveys

Gravitational Instability is nonlinear Baryons governed by hydrodynamics Radiation Field affects and is affected by structure Stars form, Supernovae explode, …

Dark Matter Dark Energy Neutrino Mass Inflation

June 27, 2008 Scott Dodelson 3

Progress

Spring 07

Summer 07

Fall 07 Winter 08

Spring 08

Summer 08

FRA Grant

KICP, TAG Investments

560 Core Cluster at New Muon Lab

Task Force Report

ANL LDRD

DOE Lab Meeting

1000 Core Cluster at New Muon Lab

DOE Dark Energy Grant

Presentation to PAC

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Projects Using the Cluster1. Tinker, Kravtsov et al. 2008, ApJ in press http://arxiv.org/abs/0803.2706 "Toward a halo mass function for precision cosmology: the limits

of universality" The project has used the KICP/FNAL cluster for analyses of billion particle cosmological simulations aimed at calibrating predictions for halo mass function and its evolution to an accuracy of a few per cent. Figures 6 and/or 7 from the above paper can be used to illustrate results of the project.

2. Brant Robertson, Andrey Kravtsov have used the cluster to perform simulationsof dwarf galaxy mergers with dark halos. The project is aimed at exploring possible morphological signatures of such "phantom mergers" to constrain incidence of pure dark halos using available data. The draft of a paper is being prepared for submission (planned submission in the next several months).

3. Konstantinos Tassis, Nick Gnedin, Andrey Kravtsov are using the cluster to run the first cosmological simulations of galaxy formation with 3D radiative transfer, molecular hydrogen formation on dust and its self-shielding from dissociating radiation. The simulations are using a model for star formation that is based on molecular hydrogen. Gnedin, N. Y., Tassis, K., Kravtsov, A. V., in preparation "Molecular-Hydrogen-Based Star Formation Prescription for Cosmological Simulations"

4. Brant Robertson, Andrey Kravtsov, Jeremy Tinker are using the cluster to run Monte Carlo calculations of mass functions and bias of dark matter halos in different models for halo collapse (using different collapse barriers to reproduce simulation results). The aim of the project is to understand the barrier required to reproduce the simulation results and implications for halo formation.

5. Robyn Levine, Nick Gnedin, Andrey Kravtsov, Andrew Hamilton (Univ. of Colorado) are running simulations of the circumnuclear region of a supermassive black hole within a cosmological volume. The goal of this project is to understand the formation and evolution of supermassive black holes and their feedback on large-scale distribution of mass in the universe. Levine, R, Gnedin, N. Y., Hamilton, A. J. S., Kravtsov, A. V., ApJ in press http://arxiv.org/abs/0711.3478 "Resolving Gas Dynamics in the Circumnuclear Region of a Disk Galaxy in a Cosmological Simulation" Levine, R, Gnedin, N. Y., Hamilton, A. J. S., Kravtsov, A. V., in preparation "Matter Transport in the Host Galaxy of a Supermassive Black Hole“

6. Maria Beltran, Wayne Hu have used the cluster for calculating some MCMC chains for a work in progress about the impact of future BAO surveys on the determination of the isocurvature amplitude of the curvaton and the degeneracies in two other cosmological parameters: the equation of state of the DE and the spatial curvature.

7. Marcos Lima, Hiroaki Oyaizu, Wayne Hu run N-body simulations of f(R) modified gravity to study the impact on nonlinear growth of structure and help distinguish modified gravity from dark energy models. The interesting results is that such models have a unique signature in P(k) at k~0.1h/Mpc because gravity is stronger outside halos (so there is more power on those scales compared to LCDM). The effect is shown in Fig. 11 of the paper (http://yummy.uchicago.edu/misc/methodpaper.pdf) H. Oyaizu, "Nonlinear evolution in f(R) cosmologies I: Methodology", in prep. H. Oyaizu, M. Lima, W. Hu, "Nonlinear evolution in f(R) cosmologies II: Power Spectrum", in prep. M. Lima, H. Oyaizu, W. Hu, "Nonlinear evolution in f(R) cosmologies III: Halo abundance and bias", in prep.

8. Qizhi Zhang, Steve Kulhmann, Peter van Gemmeren (ANL) use the cluster to manage the SQL database for the DES-related simulation work.

9. Douglas Rudd, Andrey Kravtsov have been running cluster simulations for convergence studies within the framework of an international Galaxy Cluster Comparison Project.

10. Ben Dilday is working on the measurements of the type-Ia SN rate from the SDSS-II SN Survey. Dilday, B, et al, "Rate of type-Ia SNe at z<0.25 from the SDSS-II SN Survey" Dilday, B, et al, "Rate of type-Ia SNe in galaxy clusters from the SDSS-II SN Survey" both in prep.

11. Sheng Wang is modeling CMB anisotropies in modified gravity models. Fang et al.,"Challenges for the Self-accelerating Braneworld Model on the Horizon from the CMB", in prep.

12. The VERITAS group at U of Chicago is using the cluster to run simulations of very-high-energy gamma rays hitting the atmosphere and being reconstructed by our detector. These simulations will have an important impact in all the VERITAS papers under preparation.  

June 27, 2008 Scott Dodelson 5

E.g. Was Einstein Right?Marcos Lima, Hiroaki Oyaizu,

Wayne Hu run N-body simulations of f(R) modified gravity to study the impact on nonlinear growth of structure and help distinguish modified gravity from dark energy models.

H. Oyaizu, "Nonlinear evolution in f(R) cosmologies I: Methodology", in prep.

H. Oyaizu, M. Lima, W. Hu, "Nonlinear evolution in f(R) cosmologies II: Power Spectrum", in prep.

M. Lima, H. Oyaizu, W. Hu, "Nonlinear evolution in f(R) cosmologies III: Halo abundance and bias", in prep.

June 27, 2008 Scott Dodelson 6

Particle [Astro] Physics and the Brain

Litke

Ermentrout

Symmetry

June 27, 2008 Scott Dodelson 7

Exploratory Meeting (June 2007)

Dodelson (FNAL) with Murray Sherman (Chair, Dept. of Neurobiology, UC) & Sam Sisodia (Director, Center for Neurobiology, UC) . Suggested two step process:

1. Invite Visiting Committee (e.g. Abbott, Koch, Woody, Litke) to FNAL/UC to scout out areas of overlap [$5-10k]

2. Highlight these areas in joint workshop [$20k]