Picosecond excitation of jet-cooled hydrogen-bonded systems: Dispersed fluorescence and time-resolved studies of methyl salicylatea

Long progressions involving frequency intervals of 180 cm^(−1) are observed in the fluoresence of MS for 3327.5 Å excitation. (AIP

Observation of intracavity absorption of molecules in supersonic beams

Intracavity absorption studies of DMT and I2 are reported at rotational and vibrational temperatures of <0.1 K and 16 K, respectively

(2,0) theory on circle fibrations

We consider (2,0) theory on a manifold M_6 that is a fibration of a spatial S^1 over some five-dimensional base manifold M_5. Initially, we study the free (2,0) tensor multiplet which can be described in terms of classical equations of motion in six dimensions. Given a metric on M_6 the low energy effective theory obtained through dimensional reduction on the circle is a Maxwell theory on M_5. The parameters describing the local geometry of the fibration are interpreted respectively as the metric on M_5, a non-dynamical U(1) gauge field and the coupling strength of the resulting low energy Maxwell theory. We derive the general form of the action of the Maxwell theory by integrating the reduced equations of motion, and consider the symmetries of this theory originating from the superconformal symmetry in six dimensions. Subsequently, we consider a non-abelian generalization of the Maxwell theory on M_5. Completing the theory with Yukawa and phi^4 terms, and suitably modifying the supersymmetry transformations, we obtain a supersymmetric Yang-Mills theory which includes terms related to the geometry of the fibration.Comment: 24 pages, v2 References added, typos correcte

PATHOGENESIS OF THE GLOMERULONEPHRITIS OF NZB/W MICE

The development of glomerulonephritis in NZB/W mice is closely related to the formation of antinuclear, particularly anti-DNA, antibodies. The developing inflammatory glomerular lesions are characterized by the deposition of γG- and β1C-globulins plus DNA and possibly other nuclear antigens, presumably as complexes, in a granular to lumpy pattern along the capillary walls and in the mesangia. Elution studies revealed the γG-globulin in the glomeruli to be largely γG2A-type antibody to soluble nuclear antigens. Enhancement of the antinuclear antibody response by active immunization of young NZB/W mice with DNA-methylated BSA hastens the development and increases the severity of the glomerulonephritis. Similarly, injections of soluble DNA into NZB/W mice with circulating anti-DNA antibodies but with as yet little nephritis causes rapid progression of nephritis

Quantum limit of photothermal cooling

We study the problem of cooling a mechanical oscillator using the photothermal (bolometric) force. Contrary to previous attempts to model this system, we take into account the noise effects due to the granular nature of photon absorption. This allows us to tackle the cooling problem down to the noise dominated regime and to find reasonable estimates for the lowest achievable phonon occupation in the cantilever

Suppression of Giant Magnetoresistance by a superconducting contact

We predict that current perpendicular to the plane (CPP) giant magnetoresistance (GMR) in a phase-coherent magnetic multilayer is suppressed when one of the contacts is superconducting. This is a consequence of a superconductivity-induced magneto-resistive (SMR) effect, whereby the conductance of the ferromagnetically aligned state is drastically reduced by superconductivity. To demonstrate this effect, we compute the GMR ratio of clean (Cu/Co)_nCu and (Cu/Co)_nPb multilayers, described by an ab-initio spd tight binding Hamiltonian. By analyzing a simpler model with two orbitals per site, we also show that the suppression survives in the presence of elastic scattering by impurities.Comment: 5 pages, 4 figures. Submitted to PR

Gravity tests with INPOP planetary ephemerides

In this paper, we present several gravity tests made in using the last INPOP08 planetary ephemerides. We first propose two methods to estimate the PPN parameter $\beta$ and its correlated value, the Sun J2 and we discuss the correlation between the Sun J2 and the mass of the asteroid ring. We estimate possible advance in the planet perihelia. In the end we show that no constant acceleration larger than 1/4 the Pioneer anomaly can affect the planets of our solar system.Comment: 11 pages. submitted to proceedings of IAU symposium 264 "Relativity in Fundamental Astronomy: Dynamics, Reference Frames and Data analysis

Spectral geometry, homogeneous spaces, and differential forms with finite Fourier series

Let G be a compact Lie group acting transitively on Riemannian manifolds M and N. Let p be a G equivariant Riemannian submersion from M to N. We show that a smooth differential form on N has finite Fourier series if and only if the pull back has finite Fourier series on

Superconducting Proximity Effect and Universal Conductance Fluctuations

We examine universal conductance fluctuations (UCFs) in mesoscopic normal-superconducting-normal (N-S-N) structures using a numerical solution of the Bogoliubov - de Gennes equation. We discuss two cases depending on the presence (``open'' structure) or absence (``closed'' structure) of quasiparticle transmission. In contrast to N-S structures, where the onset of superconductivity increases fluctuations, we find that UCFs are suppressed by superconductivity for N-S-N structures. We demonstrate that the fluctuations in ``open'' and ``closed'' structures exhibit distinct responses to an applied magnetic field and to an imposed phase variation of the superconducting order parameter.Comment: (4 pages, 5 figures). Corrected typos in equations, added references, changed Fig. 5 and its discussions. Phys. Rev. B, accepted for publicatio

A Hartree-Fock Study of Persistent Currents in Disordered Rings

For a system of spinless fermions in a disordered mesoscopic ring, interactions can give rise to an enhancement of the persistent current by orders of magnitude. The increase in the current is associated with a charge reorganization of the ground state. The interaction strength for which this reorganization takes place is sample-dependent and the log-averages over the ensemble are not representative. In this paper we demonstrate that the Hartree-Fock method closely reproduces results obtained by exact diagonalization. For spinless fermions subject to a short-range Coulomb repulsion U we show that due to charge reorganization the derivative of the persistent current is a discontinuous function of U. Having established that the Hartree-Fock method works well in one dimension, we present corresponding results for persistent currents in two coupled chains.Comment: 4 pages, 6 figures, Submitted to Phys. Rev.