Transportation distances and noise sensitivity of multiplicative Lévy SDE with applications

This article assesses the distance between the laws of stochastic differential equations with multiplicative Lévy noise on path space in terms of their characteristics. The notion of transportation distance on the set of Lévy kernels introduced by Kosenkova and Kulik yields a natural and statistically tractable upper bound on the noise sensitivity. This extends recent results for the additive case in terms of coupling distances to the multiplicative case. The strength of this notion is shown in a statistical implementation for simulations and the example of a benchmark time series in paleoclimate.     

Exciton fine structure splitting of single InGaAs self-assembled quantum dots

We show how the resonant absorption of the ground state neutral exciton confined in a single InGaAs self-assembled quantum dot can be directly observed in an optical transmission experiment. A spectrum of the differential transmitted intensity is obtained by sweeping the exciton energy into resonance with laser photons exploiting the voltage induced Stark-shift. We describe the details of this experimental technique and some example results which exploit the 1 μeV spectral resolution. In addition to the fine structure splitting of the neutral exciton and an upper bound on the homogeneous linewidth at 4.2 K, we also determine the transition electric dipole moment.     

Proof of the Cases <Emphasis Type="Italic">p</Emphasis>≤ 7 of the Lieb-Seiringer Formulation of the Bessis-Moussa-Villani Conjecture

It is shown that the polynomial λ (t)=Tr[(A+ tB)^p] has nonnegative coefficients when p≤ 7 and A and B are any two complex positive semidefinite n× n matrices with arbitrary n. This proves a general nontrivial case of the Lieb-Seiringer formulation of the Bessis-Moussa-Villani conjecture which is a long standing problem in theoretical physics.     

Photoacoustic spectroscopy with quantum cascade distributed-feedback lasers

We present photoacoustic (PA) spectroscopy measurements of carbon dioxide, methanol, and ammonia. The light source for the excitation was a single-mode quantum cascade distributed-feedback laser, which was operated in pulsed mode at moderate duty cycle and slightly below room temperature. Temperature tuning resulted in a typical wavelength range of 3cm(-1)at a linewidth of 0.2cm(-1). The setup was based on a Herriott multipass arrangement around the PA cell; the cell was equipped with a radial 16-microphone array to increase sensitivity. Despite the relatively small average laser power, the ammonia detection limit was 300 parts in 10(9)by volume.     

Fluorinated N-Arylaminoarylmethanephosphonic Acids and Bisfunctional Derivatives

Abstract

Aminophosphonic acids and corresponding derivatives are of widespread biological and biochemical interest. Especially fluorinated and aromatically substituted compounds ac-ting as antibacterial agents and showing fbngicidal activities are important for medicine and agriculture.     

Menthyl Substituted Phosphorus Compounds: Synthesis,Structures and NMR Studies

Abstract

Menthyl-substituted phosphorus compounds were synthesized:

(R=CH₃, C₂H₅, i-C₃H₇, t-C₄H₉, C₆H₅, L-Men, D-Men; Men=Menthyl) H-1- and C-13-NMR-spectra were treated by one- and two-dimensional methods to obtain stereospecific shift- and coupling-parameters. Problems of chiral, pseudo-chiral, pro-chiral and pseudo-pro-chiral compounds are discussed. Aromatic-ring-current-effects were calculated based on theories of Johnson/Bovey and Haigh/Mallion. Novel computer programs JOBO and HAMA were designed for convenient evaluation of ring-current-effects. The methods are demonstrated comparing Mosher's menthyl- und neo-menthylphosphineoxides L-Men(C₆H₅)(CH₃)PO and neo-Men(C₆H₅)(CH₃)PO R_(p) and S_(p) configurations. The programs may be obtained from the authors on request.