We define Hodge structures as representations, and introduce the Mumford–Tate group MT(H) of a rational Hodge structure. We give a characterization of MT(H) based on properties of reductive groups, and study it for elliptic curves and their powers. We define what it means for a Hodge structure to arise from an abelian variety (as is the case for K3 surfaces), and then focus on cases in which th...

We report high-resolution hard x-ray photoemission spectroscopy results on (Ga,Mn)As films as a function of Mn doping. Supported by theoretical calculations we identify, for both low (1%) and high (13%) Mn doping values, the electronic character of the states near the top of the valence band. Magnetization and temperature-dependent core-level photoemission spectra reveal how the delocalized cha...

Available online 30 October 2014

Stable dark red (M = Al) or dark green (M = Ga) neutral radicals {[PhB(mu-NtBu)2]2M} are obtained by the oxidation of their corresponding anions with iodine, and EPR spectra supported by DFT calculations show that the spin density is equally delocalized over all four nitrogen atoms in these spiroconjugated systems.

We report on electrical measurements of the effective density of states in the ferromagnetic semiconductor material (Ga,Mn)As. By analyzing the conductivity correction to an enhanced electron-electron interaction the electrical diffusion constant was extracted for (Ga,Mn)As samples of different dimensionality. Using the Einstein relation allows us to deduce the effective density of states of (G...

Let O denote the ring of integers in a p-adic local field. Recall that O-modules are formal groups with an O-action such that the induced action on the Lie algebra is via scalars. In the paper this notion is generalised to finite flat group schemes. It is shown that the usual properties carry over. For example, Cartier duality holds with the multiplicative group replaced by the Lubin–Tate group...

Six new compounds [(CpTi)X, Cp=upsilon(nabla)-c(nabla)H(nabla), X=Ge, Ga, B) have been prepared and their Keggin structures determined by elementary analysis, IR, UV, (infinity)H NMR and (infinity for all)WNMR spectrometry. The results show that the complexes retain Keggin structure. The complexes exhibit antitumoral activity in vitro as shown by MTT experiment.

We establish formulae for the Iwasawa invariants of Mazur–Tate elements of cuspidal eigenforms, generalizing known results in weight 2. Our first theorem deals with forms of “medium” weight, and our second deals with forms of small slope. We give examples illustrating the strange behavior which can occur in the high weight, high slope case.