VLT/UVES shows no cosmological variability of alpha

The cosmological variability of alpha is probed from individual observations of pairs of FeII lines. This procedure allows a better control of the systematics and avoids the influence of the spectral shifts due to ionization inhomogeneities in the absorbers and/or non-zero offsets between different exposures. Applied to the FeII lines of the metal absorption systems at zabs = 1.839 in Q1101--264 and at zabs = 1.15 in HE0515--4414 observed by means of UVES at the ESO-VLT, it provides da/a = 0.4 (+/- 1.5 stat)x10^{-6}. The result is shifted with respect to the Keck/HIRES mean da/a = -5.7(+/- 1.1 stat})x10^{-6} (Murphy et al. 2004) at a high confidence level (95%). Full details of this work are given in Levshakov et al (2005)Comment: 3 pages, 1 postscript figur

Financialising the State : Recent development in fiscal and monetary policy

Understanding the nature of state financialisation is crucial to ensure definancialisation efforts are successful. This paper provides a structured overview of the emerging literature on financialisation and the state. We define financialisation of the state broadly as the changed relationship between the state, understood as sovereign with duties and accountable towards its citizens, and financial markets and practices, in ways that can diminish those duties and reduce accountability. We then argue that there are four ways in which financialisation works in and through public institutions and policies: adoption of financial motives, advancing financial innovation, embracing financial accumulation strategies, and directly financialising the lives of citizens. Organising our review around the two main policy fields of fiscal and monetary policy, four definitions of financialisation in the context of public policy and institutions emerge. When dealing with public expenditure on social provisions financialisation most often refers to the transformation of public services into the basis for actively traded financial assets. In the context of public revenue, financialisation describes the process of creating and deepening secondary markets for public debt, with the state turning into a financial market player. Finally, in the realm of monetary policy financial deregulation is perceived to have paved the way for financialisation, while inflation targeting and the encouragement, or outright pursuit, of market-based short-term liquidity management among financial institutions constitute financialised policies

Holographic recording of fast events on a CCD camera

We report on holographic recording of nanosecond events on a conventional CCD camera. Three frames of an air-discharge event, with resolution of 5.9 ns and frame interval of 12 ns, are recorded in a single CCD frame. Each individual frame is reconstructed by digital filtering of the CCD frame, since successively recorded holograms are centered at different carrier frequencies in the spatial frequency domain

Holographic recording of laser-induced plasma

We report on a holographic probing technique that allows for measurement of free-electron distribution with fine spatial detail. Plasma is generated by focusing a femtosecond pulse in air. We also demonstrate the capability of the holographic technique of capturing the time evolution of the plasma-generation process

Probing fundamental constant evolution with redshifted conjugate-satellite OH lines

We report Westerbork Synthesis Radio Telescope and Arecibo Telescope observations of the redshifted satellite OH-18cm lines at $z \sim 0.247$ towards PKS1413+135. The "conjugate" nature of these lines, with one line in emission and the other in absorption, but with the same shape, implies that the lines arise in the same gas. The satellite OH-18cm line frequencies also have different dependences on the fine structure constant $\alpha$, the proton-electron mass ratio $\mu = m_p/m_e$, and the proton gyromagnetic ratio $g_p$. Comparisons between the satellite line redshifts in conjugate systems can hence be used to probe changes in $\alpha$, $\mu$, and $g_p$, with few systematic effects. The technique yields the expected null result when applied to Cen.A, a nearby conjugate satellite system. For the $z \sim 0.247$ system towards PKS1413+135, we find, on combining results from the two telescopes, that $[\Delta G/G] = (-1.18 \pm 0.46) \times 10^{-5}$ (weighted mean), where $G = g_p [\mu \alpha^2]^{1.85}$; this is tentative evidence (with $2.6 \sigma$ significance, or at 99.1% confidence) for a smaller value of $\alpha$, $\mu$, and/or $g_p$ at z~0.247, i.e. at a lookback time of ~2.9 Gyrs. If we assume that the dominant change is in $\alpha$, this implies $[\Delta \alpha /\alpha ] = (-3.1 \pm 1.2) \times 10^{-6}$. We find no evidence that the observed offset might be produced by systematic effects, either due to observational or analysis procedures, or local conditions in the molecular cloud.Comment: 4 pages, 2 figures; accepted for publication in Astrophysical Journal Letters

Imaging of Alignment, Deformation and Dissociation of CS2 Molecules using Ultrafast Electron Diffraction

Imaging the structure of molecules in transient excited states remains a challenge due to the extreme requirements for spatial and temporal resolution. Ultrafast electron diffraction from aligned molecules (UEDAM) provides atomic resolution and allows for the retrieval of structural information without the need to rely on theoretical models. Here we use UEDAM and femtosecond laser mass spectrometry (FLMS) to investigate the dynamics in carbon disulfide (CS2) following the interaction with an intense femtosecond laser pulse. We have retrieved images of ground state and excited molecules with 0.03 {\AA} precision. We have observed that the degree of alignment reaches an upper limit at laser intensities below the ionization threshold, and found evidence of structural deformation, dissociation, and ionization at higher laser intensities

Dynamics of filament formation in a Kerr medium

We have studied the large-scale beam breakup and filamentation of femtosecond pulses in a Kerr medium. We have experimentally monitored the formation of stable light filaments, conical emission, and interactions between filaments. Three major stages lead to the formation of stable light filaments: First the beam breaks up into a pattern of connected lines (constellation), then filaments form on the constellations, and finally the filaments release a fraction of their energy through conical emission. We observed a phase transition to a faster filamentation rate at the onset of conical emission. We attribute this to the interaction of conical emissions with the constellation which creates additional filaments. Numerical simulations show good agreement with the experimental results