Research Interests

Cosmic Microwave Background

The Cosmic Microwave Background is one of the most important observables in the present-day cosmology and one of our best windows onto the early Universe and the physics at the extremely high energies. The observations of the Planckian shape of the spectral dependence of its intensity provided a direct inconvertible evidence in favor of a hot and dense phase of the evolution of the Universe and thus has long been considered one of the pillars of the Big Bang cosmological model. The Cosmic Microwave Background photons are thought to be left over after the dense and hot phase of the initial evolution of the Universe, which subsequently cooled down to the currently observed effective temperature of only 2.7K. The Cosmic Microwave Background is not completely isotropic. This is because small deviations from the overall homogeneity had to be present at the very early Universe to give rise to the currently observed Universe of galaxies and their structures. They also thus had to leave their imprints on the microwave background. The Cosmic Microwave Background anisotropy both of the total intensity as well as polarization has indeed been detected. The studies and observations of the CMB fluctuations have revolutionized, and keep on doing so, the cosmology and have propelled its transformation into a data-driven, high precision science.

CMB data set analysis

A full exploitation of the potential hidden in the Cosmic Microwave Background Anisotropy calls for progressively more complicated experiments observing the sky for long periods of time, in multiple frequency bands with help of hundreds and thousands of detectors. The data sets produced by the CMB experiments are thus by necessity large in size and complex in structure with the sky signal in the measurements dominated by instrumental and sky noise and potentially systematic effects. They require advanced and sophisticated data analysis methods and software. As a result, the CMB data analysis has established itself as a stand alone research mode complementing the theoretical and instrumental studies. The modern CMB data analysis is a cross-dysciplinary effort performed at the intersection of the statistics, signal processing, numerical methods, cosmology, instrumentation and computer programming.

High performance scientific computing

The successful data analysis of the modern CMB data set relies on efficient, massively parallel, numerical codes, implementing the cutting edge numerical algorithms. The data analysis of the most of the recent and future experiments have been and will be exploiting some of the largest unclassified parallel computers. The high performance scientific computing is thus unavoidably at the core of the present-day CMB data analysis effort.

Main current projects

• ANR-MIDAS09 - ANR-funded project on high performance tools for CMB data analysis (project coordinator);
• EBEX - CMB B-mode balloon experiment (senior data analyst and co-I);
• POLARBeaR - CMB B-mode ground-based experiment (senior data analyst and co-I);
• Planck - ESA CMB satellite (data analyst, Core Team member, HFI/LFI Associate).

Software distribution

The following software products are distributed here under a Free Software Public Gnu Licence:

Selected Publications

Stompor, R., Leach, S., Stivoli, F., Baccigalupi, C.,
Maximum Likelihood algorithm for parametric component separation in CMB experiments
Monthly Notices of RAS, 392, 216, 2009, also available as arXiv:0804.2645

Stompor, R. & White, M.,
The effects of low temporal frequency modes on minimum variance maps from PLANCK,
Astronomy & Astrophysics, 419, 783, 2004.

Stompor, R., et al,
The MAXIMA Experiment: Latest Results and Consistency Tests,
C.R. Physique, 4, 841, 2003.

Stompor, R., et al.,
Making maps of the Cosmic Microwave Background: The MAXIMA example,
Physical Review D., 65, 022033, 2002.

Stompor, R., et al.,
Cosmological Implications of the MAXIMA-I High Resolution CMB anisotropy Measurement,
The Astrophysical Journal Letters, 561, L7, 2001.

Hanany, S., et al.,
MAXIMA-1: A Measurement of the Cosmic Microwave Background Anisotropy on angular scales of 10 arcminutes to 5 degrees,
The Astrophysical Journal Letters, 545, 5, 2000.

Stompor, R., Banday, A.J., & Górski, K.M.,
Flat dark matter models with hybrid adiabatic plus isocurvature initial conditions,
The Astrophysical Journal, 463, 8, 1996.

Stompor, R., Górski, K.M., & Banday, A.J.,
COBE-DMR normalisation for inflationary flat dark matter models,
Monthly Notice of R A S, 277, 1225, 1995.

Górski, K.M., Stompor, R., & Juszkiewicz, R.,
CDM and degree scale cosmic microwave background anisotropies statistics after COBE,
The Astrophysical Journal Letters, 410, L1, 1993.

Centre National de la Recherche Scientifique Laboratoire Astroparticule et Cosmologie Equipe de Traitement des Données et Simulations (ADAMIS)

Contact: Radek Stompor (radek(at)apc(dot)univ(dash)paris7(dot)fr) © 2007 rs