Composite fields, generalized hypergeometric functions and the U(1)YU(1)_Y symmetry in the AdS/CFT correspondence

We discuss the concept of composite fields in flat CFT as well as in the context of AdS/CFT. Furthermore we show how to represent Green functions using generalized hypergeometric functions and apply these techniques to four-point functions. Finally we prove an identity of $U(1)_Y$ symmetry for four-point functions.Comment: 12 pages, 2 figure

Absorption of Ultrashort Laser Pulses in Strongly Overdense Targets

We report on the first absorption experiments of sub-10 fs high-contrast Ti:Sa laser pulses incident on solid targets. The very good contrast of the laser pulse assures the formation of a very small pre-plasma and the pulse interacts with the matter close to solid density. Experimental results indicate that p-polarized laser pulses are absorbed up to 80 percent at 80 degrees incidence angle. The simulation results of PSC PIC code clearly confirm the observations and show that the collisionless absorption works efficiently in steep density profiles

Compact strain-sensitive flexible photonic crystals for sensors

A promising fabrication route to produce absorbing flexible photonic crystals is presented, which exploits self-assembly during the shear processing of multi-shelled polymer spheres. When absorbing material is incorporated in the interstitial space surrounding high-refractive-index spheres, a dramatic enhancement in the transmission edge on the short-wavelength side of the band gap is observed. This effect originates from the shifting optical field spatial distribution as the incident wavelength is tuned around the band gap, and results in a contrast up to 100 times better than similar but nonabsorbing photonic crystals. An order-of-magnitude improvement in strain sensitivity is shown, suggesting the use of these thin films in photonic sensors

Semiautomatic Method for the Separation and Determination of Total Triiodthyronine and Thyroxine in Serum

A semiautomatic procedure is presented for the separate determination of total T3 and T4 in serum in approximately 10 hrs simultaneously in 25 samples. Removal of the thyroid hormones from the serum, separation of T3 from T4 and concentration of the peaks were achieved in a closed system, consisting of three consecutive columns. The automatic microchemical iodine determination of T3 and T4 respectively, had a sensivity of less than 0.5 ng. Recovery for T3 was 87 % and for T4 88%. High accuracy and reproducibility could be shown with pooled control scrum. The overspill of T4 into T3 was less than 0.1 % of total T4. The means of total scrum T8 and T4 were 1.46 ± 0.20 (S. D.) //g/1 and 76.5 ± 10.7 ^g/1 respectively for euthyroid controls. In patients with nontoxic goiter the T4 levels were significantly lower than in euthyroid controls, whereas the T3 levels and the T3:T., ratio were significantly higher. Es wird eine semiautomatische Methode für die simultane Analyse von 25 Proben beschrieben, welche die getrennte Bestimmung des Gcsamt-Trijodthyronins und-Thyroxins im Serum innerhalb von etwa 10 Stunden erlaubt. Die Abtrennung der Schilddrüscnhormon

Collective Computation in Object-based Parallel Programming Languages

Bal, H.E. [Promotor

A Signature of Cosmic Strings Wakes in the CMB Polarization

We calculate a signature of cosmic strings in the polarization of the cosmic microwave background (CMB). We find that ionization in the wakes behind moving strings gives rise to extra polarization in a set of rectangular patches in the sky whose length distribution is scale-invariant. The length of an individual patch is set by the co-moving Hubble radius at the time the string is perturbing the CMB. The polarization signal is largest for string wakes produced at the earliest post-recombination time, and for an alignment in which the photons cross the wake close to the time the wake is created. The maximal amplitude of the polarization relative to the temperature quadrupole is set by the overdensity of free electrons inside a wake which depends on the ionization fraction $f$ inside the wake. The signal can be as high as $0.06 {\rm \mu K}$ in degree scale polarization for a string at high redshift (near recombination) and a string tension $\mu$ given by $G \mu = 10^{-7}$.Comment: 8 pages, 3 figure