Salman Habib
A5082927374- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Astronomy and Astrophysical Research
- Scientific Research and Discoveries
- Radio Astronomy Observations and Technology
- Computational Physics and Python Applications
- Advanced Data Storage Technologies
- Distributed and Parallel Computing Systems
- Quantum Mechanics and Applications
- Stellar, planetary, and galactic studies
- Quantum chaos and dynamical systems
- Astrophysics and Cosmic Phenomena
- Advanced Thermodynamics and Statistical Mechanics
- Dark Matter and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Particle physics theoretical and experimental studies
- Quantum Information and Cryptography
- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Adaptive optics and wavefront sensing
- Cold Atom Physics and Bose-Einstein Condensates
- Scientific Computing and Data Management
- Solar and Space Plasma Dynamics
- Black Holes and Theoretical Physics
- Nonlinear Dynamics and Pattern Formation
Karachi Institute of Radiotherapy and Nuclear Medicine
2007-2024
Argonne National Laboratory
2014-2023
University of Chicago
2013-2022
Office of Scientific and Technical Information
1999-2022
National Technical Information Service
2022
Pakistan Institute of Medical Sciences
2022
Los Alamos National Laboratory
2003-2018
Fermi National Accelerator Laboratory
2011-2015
Deutsches Elektronen-Synchrotron DESY
2015
Institute of Radiotherapy and Nuclear Medicine
2007-2013
DESI (Dark Energy Spectroscopic Instrument) is a Stage IV ground-based dark energy experiment that will study baryon acoustic oscillations (BAO) and the growth of structure through redshift-space distortions with wide-area galaxy quasar redshift survey. To trace underlying matter distribution, spectroscopic targets be selected in four classes from imaging data. We measure luminous red galaxies up to $z=1.0$. probe Universe out even higher redshift, target bright [O II] emission line $z=1.7$....
A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of exciting science opportunities next decade. The Large Synoptic Survey Telescope (LSST) have an effective aperture 6.7 meters and imaging camera field view 9.6 deg^2, be devoted ten-year 20,000 deg^2 south +15 deg. Each pointing imaged 2000 times fifteen second exposures six broad from 0.35 1.1 microns, total point-source depth r~27.5. LSST Science Book describes basic...
The rate at which pure initial states deteriorate into mixtures is computed for a harmonic oscillator interacting with an environment in thermal equilibrium. decoherence process resulting from this interaction selects set of characterized by maximal stability (or minimal loss predictive power) can be quantified the increase either linear or statistical entropy. In weak coupling limit, coherent are shown to produce least entropy, thus becoming natural counterparts classical points phase space.
We present the science case, reference design, and project plan for Stage-4 ground-based cosmic microwave background experiment CMB-S4.
Near-future cosmological observations targeted at investigations of dark energy pose stringent requirements on the accuracy theoretical predictions for clustering matter. Currently, N-body simulations comprise only viable approach to this problem. In paper we demonstrate that can indeed be sufficiently controlled fulfill these needs ongoing and near-future weak lensing surveys. By performing a large suite simulation comparison convergence tests show results nonlinear matter power spectrum...
Modern sky surveys are returning precision measurements of cosmological statistics such as weak lensing shear correlations, the distribution galaxies, and cluster abundance. To fully exploit these observations, theorists must provide predictions that at least accurate measurements, well robust estimates systematic errors inherent to modeling process. In nonlinear regime structure formation, this challenge can only be overcome by developing a large-scale, multi-physics simulation capability...
Abstract CMB-S4—the next-generation ground-based cosmic microwave background (CMB) experiment—is set to significantly advance the sensitivity of CMB measurements and enhance our understanding origin evolution universe. Among science cases pursued with CMB-S4, quest for detecting primordial gravitational waves is a central driver experimental design. This work details development forecasting framework that includes power-spectrum-based semianalytic projection tool, targeted explicitly toward...
We introduce and discuss the problem of quantum feedback control in context established formulations classical theory, examining conceptual analogies essential differences. describe application state-observer based laws, familiar to systems apply our methods particular case switching state a particle double-well potential.
The power spectrum of density fluctuations is a foundational source cosmological information. Precision probes targeted primarily at investigations dark energy require accurate theoretical determinations the in nonlinear regime. To exploit observational future surveys, accuracy demands on theory are 1% level or better. Numerical simulations currently only way to produce sufficiently error-controlled predictions for spectrum. very high computational cost (precision) N-body major obstacle...
We present a precise estimate of the bulk virial scaling relation halos formed via hierarchical clustering in an ensemble simulated cold dark matter cosmologies. The result is insensitive to cosmological parameters; presence trace, dissipationless gas component; and numerical resolution down limit ~1000 particles. velocity dispersion scales with total mass as log [σDM(M,z)] = log(1082.9 ± 4.0 km s−1) + (0.3361 0.0026)log[h(z)M200/1015 M☉], h(z) being dimensionless Hubble parameter. At fixed...
We study the formation of dark matter halos in concordance ΛCDM model over a wide range redshifts, from z = 20 to present. Our primary focus is halo mass function, key probe cosmology. By performing large suite nested-box N-body simulations with careful convergence and error controls (60 box sizes 4 256 h−1 Mpc), we determine function its evolution excellent statistical systematic errors, reaching few percent most considered redshift range. Across studied probed 6 orders magnitude...
Many of the most exciting questions in astrophysics and cosmology, including majority observational probes dark energy, rely on an understanding nonlinear regime structure formation. In order to fully exploit information available from this extract cosmological constraints, accurate theoretical predictions are needed. Currently such can only be obtained costly, precision numerical simulations. This paper is third a series aimed at constructing calibration mass power spectrum Mpc scales for...
Understanding the origin of accelerated expansion Universe poses one greatest challenges in physics today. Lacking a compelling fundamental theory to test, observational efforts are targeted at better characterization underlying cause. If new form mass-energy, dark energy, is driving acceleration, redshift evolution equation state parameter w(z) will hold essential clues as its origin. To best exploit data from observations it necessary develop robust and accurate reconstruction approach,...
The statistics of dark matter halos is an essential component precision cosmology. mass distribution halos, as specified by the halo function, a key input for several cosmological probes. sizes N-body simulations are now such that, most part, results need no longer be statistics-limited, but still subject to various systematic uncertainties. Discrepancies in simulation campaigns function remain excess statistical uncertainties and roughly same size error limits set near-future observations;...
Dark matter-dominated cluster-scale halos act as an important cosmological probe and provide a key testing ground for structure formation theory. Focusing on their mass profiles, we have carried out (gravity-only) simulations of the concordance LCDM cosmology, covering range 2.10^{12}-2.10^{15} solar mass/h redshift z=0-2, while satisfying associated requirements resolution statistical control. When fitting to Navarro-Frenk-White profile, our concentration-mass (c-M) relation differs in...
SPHEREx (Spectro-Photometer for the History of Universe, Epoch Reionization, and Ices Explorer) ( http://spherex.caltech.edu ) is a proposed all-sky spectroscopic survey satellite designed to address all three science goals in NASA's Astrophysics Division: probe origin destiny our Universe; explore whether planets around other stars could harbor life; evolution galaxies. will scan series Linear Variable Filters systematically across entire sky. The data set contain R=40 spectra fir...
A basic aim of ongoing and upcoming cosmological surveys is to unravel the mystery dark energy. In absence a compelling theory test, natural approach better characterize properties energy in search clues that can lead more fundamental understanding. One way view this characterization improved determination redshift-dependence equation state parameter, w(z). To do requires robust bias-free method for reconstructing w(z) from data does not rely on restrictive expansion schemes or assumed...
Understanding the structure of matter distribution in Universe due to action gravitational instability---the creation ``cosmic web''---is complicated by lack direct analytic access complex nonlinear domain formation. Here, we suggest and apply a novel tessellation method designed for cold dark (CDM) N-body cosmological simulations. The is based on fact that initial CDM state can be described 3-dimensional manifold (in 6-dimensional phase space) remains continuous under evolution. Our...
As noted in Wikipedia, skin the game refers to having ‘incurred risk by being involved achieving a goal’, where ‘ is synecdoche for person involved, and metaphor actions on field of play under discussion’. For exascale applications development US Department Energy Exascale Computing Project, nothing could be more apt, with delivering comprehensive science-based computational that effectively exploit high-performance computing technologies provide breakthrough modelling simulation data...
We detect the kinematic Sunyaev-Zel'dovich (kSZ) effect with a statistical significance of 4.2σ by combining cluster catalogue derived from first year data Dark Energy Survey cosmic microwave background temperature maps South Pole Telescope Survey. This measurement is performed differential statistic that isolates pairwise kSZ signal, providing detection large-scale, motion clusters using redshifts photometric data. By fitting signal to theoretical template, we measure average central...
Abstract This paper introduces cosmoDC2, a large synthetic galaxy catalog designed to support precision dark energy science with the Large Synoptic Survey Telescope (LSST). CosmoDC2 is starting point for second data challenge (DC2) carried out by LSST Dark Energy Science Collaboration (LSST DESC). The based on trillion-particle, (4.225 Gpc) 3 box cosmological N -body simulation, Outer Rim run. It covers 440 deg 2 of sky area redshift z = and matches expected number densities from...
The halo occupation distribution (HOD) approach has proven to be an effective method for modeling galaxy clustering and bias. In this approach, galaxies of a given type are probabilistically assigned individual halos in N-body simulations. paper, we present fast emulator predicting the fully nonlinear galaxy–galaxy auto galaxy–dark matter cross power spectrum correlation function over range freely specifiable HOD parameters. is constructed using results from 100 models run on large ΛCDM...