The brightness and homogeneity of thermonuclear (type 1a) supernovae (SN1a) makes them excellent distance indicators, useful to probe the cosmological equation of state or the nature of the dark energy. SN1a are also a key to the chemical evolution of our galaxy and an ideal laboratory for advanced radiation hydrodynamics, combustion theory and nuclear and atomic physics. To take full advantage of new data, detailed three dimensional (3-D) radiation and hydrodynamical models are required. Some 3-D effects seem to be unavoidable for a close binary system with mass overflow, due to the interaction with the accretion disk and the companion star, the rapid rotation of the white dwarf, the physics of the ignition process, and the properties of the nuclear burning front. The present systematic study will reveal directional luminosity asymmetries and how to correct for them. By deciphering the ejection structure, it will provide new information on the explosion physics, the progenitor star, the accretion disk, and the companion star. The consistent treatment of hydrodynamics, nucleosynthesis, and radiation transport, provides the desired link between the explosion physics and the observable quantities. Tools already created by these researchers will be further developed, and applied to calculate detailed flux and polarization spectra and aspherical light curves, whose results will be compared with extensive observations.
The impact of the proposed work goes far beyond a better understanding of supernovae, including the continued development of a widely applicable hydrodynamic radiation transport code, training of students and junior researchers, and the impact on the use of supernovae as one of the main instruments of modern astronomy and cosmology.