Diffusion behavior of delta-doped Si in InAlAs/InP heterostructures

Diffusion behavior of delta-doped Si in InAlAs and InP was studied by using secondary ion mass spectroscopy. A significant broadening of the profile due to postgrowth annealing was observed in In0.52Al0.48As. In contrast, the depth profile of delta-doped Si in InP was scarcely changed by annealing. This indicates that the diffusion coefficient of delta-doped Si in InP is much smaller than that in In0.52Al0.48As. Suppression of Si diffusion by using a delta-doped InP layer as the carrier supply layer (CSL) improves the thermal stability of the InP-HEMT structures

Effects of thermal fluctuations on thermal inflation

The mechanism of thermal inflation, a relatively short period of accelerated expansion after primordial inflation, is a desirable ingredient for a certain class of particle physics models if they are not to be in contention with the cosmology of the early Universe. Though thermal inflation is most simply described in terms of a thermal effective potential, a thermal environment also gives rise to thermal fluctuations that must be taken into account. We numerically study the effects of these thermal fluctuations using lattice simulations. We conclude that though they do not ruin the thermal inflation scenario, the phase transition at the end of thermal inflation proceeds through phase mixing and is therefore not accompanied by the formations of bubbles nor appreciable amplitude of gravitational waves.Comment: 14 pages, 4 figure

Statistically-Anisotropic Tensor Bispectrum from Inflation

We develop a possibility of generating tensor non-Gaussianity in a kind of anisotropic inflation, where a $U(1)$ gauge field is kinetically coupled to a spectator scalar field. Owing to this coupling, the coherent mode of the electric field appears and softly breaks the isotropy of the Universe. We compute the bispectrum of linearly-polarized tensor perturbations sourced by the gauge field and find that it is strongly red-tilted and has distinctive statistical anisotropies including higher-order multipole moments. Interestingly, the tensor bispectra with the specific combinations of linear polarization modes are dominant, and their amplitudes depend on the different sets of multipole moments. This new type of statistically-anisotropic tensor non-Gaussianity can be potentially testable with the upcoming cosmic microwave background B-mode polarization experiments.Comment: 25 pages, 4 figure

Impending Gastric Rupture in a Neonate with Gastric Outlet Obstruction due to Malrotation

This is a case report of a neonate with impending gastric rupture due to malrotation with gastric outlet obstruction. A preoperative plain abdominal X-ray showed expansion of the gastric bubble. A barium meal demonstrated an unusual bulging of the gastric wall extending from the fundus to the body of the stomach on the greater curvature side and malrotation of the duodenal loop. At operation a malrotation with volvulus and a rupture of the seromuscular layer with bulging of the mucosa in the stomach was found. We think that this unusual bulging of the gastric wall in the barium meal is an important radiological sign of impending gastric rupture