Adelic Integrable Systems

Incorporating the zonal spherical function (zsf) problems on real and $p$-adic hyperbolic planes into a Zakharov-Shabat integrable system setting, we find a wide class of integrable evolutions which respect the number-theoretic properties of the zsf problem. This means that at {\it all} times these real and $p$-adic systems can be unified into an adelic system with an $S$-matrix which involves (Dirichlet, Langlands, Shimura...) L-functions.Comment: 23 pages, uses plain TE

Relaxation of hole spins in quantum dots via two-phonon processes

We investigate theoretically spin relaxation in heavy hole quantum dots in low external magnetic fields. We demonstrate that two-phonon processes and spin-orbit interaction are experimentally relevant and provide an explanation for the recently observed saturation of the spin relaxation rate in heavy hole quantum dots with vanishing magnetic fields. We propose further experiments to identify the relevant spin relaxation mechanisms in low magnetic fields.Comment: 5 pages, 2 figure

A Frobenius variant of Seshadri constants

We define and study a version of Seshadri constant for ample line bundles in positive characteristic. We prove that lower bounds for this constant imply the global generation or very ampleness of the corresponding adjoint line bundle. As a consequence, we deduce that the criterion for global generation and very ampleness of adjoint line bundles in terms of usual Seshadri constants holds also in positive characteristic.Comment: 16 page

Surface complexation model of aquifer pollution with heavy metals on ash and slag dump near Timişoara

For modelling of the pollutants transport process in aquifer a very important aspect has the analysis of aquifer pollution with heavy metals. The surface complexation process of heavy metals on the grains of porous-media is reversible similar to the adsorption-desorption in transport processes, in aquifer pollution, but strongly dependent of pH value. High pH values determine increasing heavy metals complexation and consequently decrease their concentration in the groundwater. Decreasing pH value leads to liberation of heavy metals from the formed complex and so an increased concentration of heavy metals in the groundwater appears. This paper presents the results obtained by using a numerical experiment using PhreeqC and PMWIN software package for the spreading of the heavy metals pollution in the aquifer of an ash and slug dump, as pollution source, near village Utvin, Timi$ County, Romania

Irreducible Killing Tensors from Third Rank Killing-Yano Tensors

We investigate higher rank Killing-Yano tensors showing that third rank Killing-Yano tensors are not always trivial objects being possible to construct irreducible Killing tensors from them. We give as an example the Kimura IIC metric were from two rank Killing-Yano tensors we obtain a reducible Killing tensor and from third rank Killing-Yano tensors we obtain three Killing tensors, one reducible and two irreducible.Comment: 10 page

Strong Spin-Orbit Interaction and Helical Hole States in Ge/Si Nanowires

We study theoretically the low-energy hole states of Ge/Si core/shell nanowires. The low-energy valence band is quasidegenerate, formed by two doublets of different orbital angular momenta, and can be controlled via the relative shell thickness and via external fields. We find that direct (dipolar) coupling to a moderate electric field leads to an unusually large spin-orbit interaction of Rashba type on the order of meV which gives rise to pronounced helical states enabling electrical spin control. The system allows for quantum dots and spin qubits with energy levels that can vary from nearly zero to several meV, depending on the relative shell thickness.Comment: 8 pages, 6 figure

Existence of solutions to a higher dimensional mean-field equation on manifolds

For $m\geq 1$ we prove an existence result for the equation $$(-\Delta_g)^m u+\lambda=\lambda\frac{e^{2mu}}{\int_M e^{2mu}d\mu_g}$$ on a closed Riemannian manifold $(M,g)$ of dimension $2m$ for certain values of $\lambda$.Comment: 15 Page

f-symbols, Killing tensors and conserved Bel-type currents

In the framework of the General Relativity we show that from three generalizations of Killing vector fields, namely f-symbols, symmetric St\"{a}ckel-Killing and antisymmetric Killing-Yano tensors, some conserved currents can be obtained through adequate contractions of the above mentioned objects with rank four tensors having the properties of Bel or Bel-Robinson tensors in Einstein spaces.Comment: 13 pages, accepted for publication in Mod. Phys. Lett.