Sökresultat

We define systems of uniaxial type, which generalize Maxwell's system of equations for uniaxial crystals. We compute the geometric invariants of these systems. Using energy estimates, we prove results on the propagation of Sobolev polarization sets. The polarization sets refine the wave front sets of vector valued distributions.

We define and study the polarization sets for vector-valued distributions. Systems of real principal type are defined, and we prove that for such systems of pseudodifferential operators we have a unique propagation of the polarization sets for the solutions.

This paper studies the solvability for square systems of classical pseudodifferential operators. We assume that the system is of principal type, i.e., the principal symbol vanishes of first order on the kernel. We shall also assume that the eigenvalues of the principal symbol close to zero have constant multiplicity. We prove that local solvability for the system is equivalent to condition (ψ) on

Installation för Art Encounters Biennale I Timisoara - verket kommer att presenteras i september 2019. Forskning pågår kring målaren Albert Varga (1900-1940) som kommer att redovisas som en del av konstverket.

It was a great surprise when Hans Lewy in 1957 presented a non-vanishing complex vector field that is not locally solvable. Actually, the vector field is the tangential Cauchy-Riemann operator on the boundary of a strictly pseudoconvex domain. Hörmander proved in 1960 that almost all linear partial differential equations are not locally solvable. This also has connections with the spectral instabi

Key message: The hormonal ratios along the barley spike regulate the development, atrophy and abortion of the spikelets and could be the mechanism by which the barley spike adapts its yield potential. Abstract: Barley (Hordeum vulgare L.) is one of the oldest cereal crops known to be cultivated since about 10,000 years. The inflorescence of cultivated barley is an indeterminate spike that produces

Recent results obtained for the 4He(γ,n) reaction prior to the facility upgrade are presented. Future plans for measuring Compton scattering from the deuteron at the upgraded facility are discussed.

The paper studies the local solvability and subellipticity for square systems of principal type. These are the systems for which the principal symbol vanishes of first order on its kernel. For systems of principal type having constant characteristics, local solvability is equivalent to condition (Ψ) on the eigenvalues. This is a condition on the sign changes of the imaginary part along the oriente

En serie av arbeten och installationer som producerades i förhållande till Gemäldegallerie i Berlins konstsamling för den 8 Berlin Biennalen - verken handlade om porträtt som föreställer en okänd person och som är utförda av okända konstnärer