Cosmology and Astrophysics     

In cosmology, one of my continuing interests has been the application of quantum field theory in curved spacetime to dynamical issues such as the suppression/generation of the cosmological constant by semiclassical backreaction, density perturbations from inflation, the quantum-classical transition in the early universe, quantum transport theory in curved spacetime, and the application of ideas from statistical physics to cosmological models. On the above subjects I have worked with several people, most notably my Ph.D. adviser Bei-lok Hu (Maryland), Esteban Calzetta (IAFE, another post-doc collaborator during graduate school days), the late Henry Kandrup, and Bill Unruh (UBC, with whom I enjoyed a memorable first post-doc), Redwan Fakir who I met at UBC when he was a graduate student, Varun Sahni (IUCAA) who I first met as a fellow post-doc at CITA in 1989, and more recently with Andreas Heinen (student at Dortmund), Katrin Heitmann, Gerard Jungman, and Carmen Molina-Paris, all of whom I met at Los Alamos.

Lately I have become interested in the dynamics of the formation of large scale structure in the universe and the associated problems of dark matter and dark energy. With the generous help of several people, I have written a parallel structure formation code called MC^2. This code is one of the centerpieces of the work at LANL whic addresses scale structure issues using observational data, e.g., from the Sloan Digital Sky Survey (SDSS). Simulations using MC^2 are now being employed in a variety of studies including weak gravitational lensing, Lyman-alpha clouds as a probe of the primordial power spectrum, code convergence issues (code verification), the generation of mock catalogs for cosmological surveys, the study of cosmological voids, the role of neutrino mass in determining the nonlinear mass power spectrum, and analysis of the galactic velocity field. We are putting some of our results out for public use as part of The Cosmic Data ArXiv. Collaborators in the activities listed above include Kev Abazajian (LANL), Scott Dodelson (FNAL), Leanne Duffy (LANL), Hume Feldman (Kansas), Josh Frieman (FNAL), Katrin Heitmann, Lam Hui (Columbia), Bhuvnesh Jain (Penn), Savvas Koushiappas (LANL), Adam Lidz (Harvard), Zarija Lukic (UIUC/LANL), Chris Miller (NOAO/CTIO), Darren Reed (LANL), Paul Ricker (UIUC), Varun Sahni, Sergei Shandarin (Kansas), Eric Switzer (Princeton), and Michael Warren (LANL).

In astrophysics, I have worked on problems in galactic dynamics, relativistic astrophysics, and more recently on two observational projects. My main collaborator in the early theory efforts was Henry Kandrup (Florida) who I first met as a post-doc in graduate school. I remain interested in chaotic dynamics in galaxies and nontrivial self-consistent solutions of the gravitational Vlasov-Poisson system of equations, truncated moment hierarchy methods for approximate solutions of the Vlasov-Poisson system, and numerical galactic dynamics on parallel supercomputers using a large particle-mesh code.

The observational projects were: (i) Obtaining constraints on the inter-galactic magnetic field using Faraday rotation of radio source polarization as a measure of the integrated magnetic field along observational lines of sight. We obtained an approximate upper limit on the field strength of 0.3 micro-Gauss/500 kpc [with Yongzhong Xu (LANL), Philipp Kronberg (LANL), and Quentin Dufton (LANL)], (ii) X-ray follow-up observations of optical targets -- giant elliptical-dominated galaxy groups found in the SDSS. The three targets were observed by XMM-Newton and found to be X-ray bright; one met the standard criteria of being a fossil group [with Alexey Voevodkin (LANL) et al. below].

Papers

Links are to the Los Alamos eprint server:

  1. Simulations and Cosmological Inference: A Statistical Model for Power Spectra means and Covariances, Michael Schneider, Lloyd Knox, Salman Habib, Katrin Heitmann, David Higdon, and Charles Nakhleh, Phys. Rev. D (submitted) arXiv:0806.1487v1
  2. The Structure of Halos: Implications for Group and Cluster Cosmology, Zarija Lukic, Darren Reed, Salman Habib, and Katrin Heitmann, Astrophys. J. (submitted) arXiv:0803.3624v1
  3. The Cosmic Code Comparison Project, Katrin Heitmann, Zarija Lukic, Patricia Fasel, Salman Habib, Michael Warren, Martin White, James Ahrens, Lee Ankeny, Ryan Armstrong, Brian O'Shea, Paul M. Ricker, Volker Springel, Joachim Stadel, and Hy Trac, Comp. Sci. Disc. (in press) arXiv:0706.1270v1
  4. X-ray Observations of Optically Selected Giant Elliptical-Dominated Galaxy Groups, Alexey Voevodkin, Christopher J. Miller, Konstantin Borozdin, Katrin Heitmann, Salman Habib, Paul Ricker, and Robert C. Nichol, Astrophys. J. (in press) arXiv:0803.3786v1
  5. Provenance in Comparitive Analysis: A Study in Cosmology, Erik W. Anderson, Claudio T. Silva, James P. Ahrens, Katrin Heitmann, and Salman Habib, Computing in Science and Engineering 10, 30 (2008)
  6. Virial Scaling of Massive Dark Matter Halos: Why Clusters Prefer a High Normalization Cosmology, Gus Evrard, John Bialek, Michael Busha, Martin White, Salman Habib, Katrin Heitmann, Michael Warren, Elena Rasia, Giuseppe Tormen, Lauro Moscardini, Chris Power, Adrian Jenkins, Liang Gao, Carlos Frenk, Volker Springel, Simon White, Juerg Diemand, Astrophys. J. 672, 122 (2008) astro-ph/0702241
  7. The Halo Mass Function: High Redshift Evolution and Universality, Zarija Lukic, Katrin Heitmann, Salman Habib, Sergei Bashinsky, and Paul M. Ricker, Astrophys. J. 671, 1160 (2007) astro-ph/0702360
  8. Cosmic Calibration: Constraints from the Matter Power Spectrum and the Cosmic Microwave Background, Salman Habib, Katrin Heitmann, David Higdon, Charles Nakhleh, and Brian Williams, Phys. Rev. D 76, 083503 (2007) astro-ph/0702348
  9. Quantitative and Comparitive Visualization applied to Cosmological Simulations, James Ahrens, Katrin Heitmann, Salman Habib, Lee Ankeney, Patrick McCormick, Jeff Inman, Ryan Armstrong, and Kwan-Liu Ma, Proceedings of the 2006 SciDAC Conference, J. Phys. Conf. Ser. 46, 526 (2006) SciDAC 2006
  10. Cosmic Calibration, Katrin Heitmann, David Higdon, Charles Nakhleh, and Salman Habib, Astrophys. J. Lett. 646, L1 (2006) astro-ph/0606154
  11. Capturing Halos at High Redshifts, Katrin Heitmann, Zarija Lukic, Salman Habib, and Paul M. Ricker, Astrophys. J. Lett. 642, L85 (2006) astro-ph/0601233
  12. Shapes and Sizes of Voids in the LCDM Universe: Excursion Set Approach, Sergei Shandarin, Hume Feldman, Katrin Heitmann, and Salman Habib, MNRAS 367, 1629 (2006) astro-ph/0509858
  13. A Faraday Rotation Search for Magnetic Fields in Large Scale Structure, Yongzhong Xu, Philipp Kronberg, Salman Habib, and Quentin Dufton, Astrophys. J. 637, 19 (2006) astro-ph/0509826
  14. Tightening Constraints from the Lyman Alpha Forest with the Flux Probability Distribution Function, Adam Lidz, Katrin Heitmann, Lam Hui, Salman Habib, Michael Rauch, and Wallace L.W. Sargent, Astrophys. J. 638, 27 (2006) astro-ph/0505138
  15. Joint Efficient Dark-Energy Investigation (JEDI): A Candidate Implementation of the NASA-DOE Joint Dark Energy Mission (JDEM), Arlin Crotts, Peter Garnavich, William Priedhorsky, Salman Habib, Katrin Heitmann, Yun Wang, Eddie Baron, David Branch, Harvey Moseley, Alexander Kutyrev, Chris Blake, Edward Cheng, Ian Dell'Antonio, John Mackenty, Gordon Squires, Max Tegmark, Craig Wheeler, Ned Wright, JEDI White Paper submitted to Dark Energy Task Force astro-ph/0507043
  16. Robustness of Cosmological Simulations I: Large Scale Structure, Katrin Heitmann, Paul Ricker, Michael Warren, and Salman Habib, Astrophys. J. Supp. 160, 28 (2005) astro-ph/0411795
  17. Inflationary Perturbations and Precision Cosmology, Salman Habib, Andreas Heinen, Katrin Heitmann, and Gerard Jungman, Phys. Rev. D 71, 043518 (2005) astro-ph/0501130
  18. The Nonlinear Cosmological Matter Power Spectrum with Massive Neutrinos I: The Halo Model, Kevork Abazajian, Eric R. Switzer, Scott Dodelson, Katrin Heitmann, and Salman Habib, Phys. Rev. D 71, 043507 (2005) astro-ph/0411552
  19. Inverse-Scattering Theory and the Density Perturbations from Inflation, Salman Habib, Katrin Heitmann, and Gerard Jungman, Phys. Rev. Lett. 94, 061303 (2005) astro-ph/0409599
  20. Characterizing Inflationary Perturbations: The Uniform Approximation, Salman Habib, Andreas Heinen, Katrin Heitmann, Gerard Jungman, and Carmen Molina-Paris, Phys. Rev. D 70, 083507 (2004) astro-ph/0406134
  21. Massive Neutrinos and the Halo Model of Large-Scale Structure, Eric Switzer, Kev Abazajian, Scott Dodelson, Salman Habib, and Katrin Heitmann, Proceedings of Neutrino 2004, Paris (2004), Nuc. Phys. B Proc. Supp. (to appear)
  22. The Inflationary Perturbation Spectrum, Salman Habib, Katrin Heitmann, Gerard Jungman, and Carmen Molina-Paris, Phys. Rev. Lett. 89, 281301 (2002) astro-ph/0208443
  23. Gravitationally Induced Neutrino Oscillation Phases in Static Spacetimes, Tanmoy Bhattacharya, Salman Habib, and Emil Mottola, Phys. Rev. D 59, 067301 (1999).
  24. Does Inflationary Particle Production suggest Omega_m < 1?, Varun Sahni and Salman Habib, Phys. Rev. Lett. 81, 1766 (1998) hep-ph/9808204
  25. Dark Matter and Massive Neutrinos, Salman Habib, Los Alamos Science 25, 180 (1997)
  26. Chaos and Noise in Galactic Potentials, Salman Habib, Henry E. Kandrup, and M. Elaine Mahon, Ap. J. 480, 155 (1997) astro-ph/9409050
  27. Chaos and Noise in a Truncated Toda Potential, Salman Habib, Henry E. Kandrup, and M. Elaine Mahon, Phys. Rev. E 53, 5473 (1996) chao-dyn/9406011
  28. Big Bang Cosmology and the Microwave Background, Salman Habib and Raymond J. Laflamme, Los Alamos Science 22, 82 (1994)
  29. Spin Dynamics of the LAGEOS Satellite in Support of a Measurement of the Earth's Gravitomagnetism, Salman Habib, Daniel E. Holz, Arkady Kheyfets, Richard A. Matzner, Warner A. Miller, and Brian W. Tollman, Phys. Rev. D 50, 6068 (1994) gr-qc/9406032
  30. Multiplicative Noise: Applications in Cosmology and Field Theory, Salman Habib, Ann. N. Y. Acad. Sci. 706 (1993) gr-qc/9308022
  31. Quantum Fluctuations with Strong Curvature Coupling, Redouane Fakir and Salman Habib, Mod. Phys. Lett. A 8, 2827 (1993)
  32. Stochastic Inflation: The Quantum Phase Space Approach, Salman Habib, Phys. Rev. D 46, 2408 (1992) gr-qc/9208006
  33. Nonlinear Noise in Cosmology, Salman Habib and Henry E. Kandrup, Phys. Rev. D 46, 5303 (1992) gr-qc/9208005
  34. Cosmological Density Perturbations with Modified Gravity, Redouane Fakir, Salman Habib, and William Unruh, Ap. J. 394, 396 (1992)
  35. Stochastic Dynamics of Coarse-Grained Quantum Fields in the Inflationary Universe, Salman Habib and Milan Mijic, UBC Report (1991)
  36. Wigner Function and Decoherence in Quantum Cosmology, Salman Habib and Raymond Laflamme, Phys. Rev. D 42, 4056 (1990)
  37. Classical Limit in Quantum Cosmology: Quantum Mechanics and the Wigner Function, Salman Habib, Phys. Rev. D 42, 2566 (1990)
  38. Wigner Functions and Density Matrices in Curved Spaces as Computational Tools, Salman Habib and Henry E. Kandrup, Ann. Phys. 191, 335 (1989)
  39. Exact Langevin Equation in a Cosmological Setting, Salman Habib and Henry E. Kandrup, Phys. Rev. D 39, 2871 (1989)
  40. Quantum Kinetic Field Theory in Curved Spacetime: Covariant Wigner Function and Liouville-Vlasov Equations, Esteban Calzetta, Salman Habib, and Bei-Lok Hu, Phys. Rev. D 37, 2901 (1988)
  41. Gravitational Landau Damping for an Isotropic Cluster of Stars, Salman Habib, Henry E. Kandrup, and Ping F. Yip, Ap. J. 309, 176 (1986)
Related Links

T-Division Research Highlights for 2005: Physical Cosmology with the Sloan Digital Sky Survey [PDF].
T-Division Research Highlights for 2005: The Cosmic Data Archive [PDF].
T-Division Research Highlights for 2005: The Morphology and Dynamics of Cosmic Voids [PDF].
The Sloan Computational Cosmology Project home page.
The WMAP CMBR satellite mission.
Gravitational Astrophysics at the University of Florida, Gainesville.
Astro-Metrology at the University of Maryland.

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Salman Habib / LANL / revised March 2008
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