A Coupling of Pseudo Nambu Goldstone Bosons to Other Scalars and Role in Double Field Inflation

We find a coupling of Pseudo Nambu Goldstone bosons (PNGBs) to other (ordinary) scalars, and consider its importance in various contexts. Our original motivation was the model of Double Field inflation [1]. We also briefly consider the role of this coupling for the case of the QCD axion.Comment: 8 pages Plain TeX, submitted to Phys. Rev. D, UMAC 94-0

New State Records for the Cicada Parasite Beetle Sandalus petrophya Knoch (Rhipiceridae)

Abstract: New state records are presented for Sandalus petrophya specimens from Nebraska and Iowa along with the currently known distribution of this beetle species

Distribution of \u3ci\u3eStrongylium Crenatum\u3c/i\u3e (Coleoptera: Tenebrionidae) in the United States and First Record From Iowa

Strongylium crenatum Mäklin (Coleoptera: Tenebrionidae) is reported from Iowa for the first time. After discovering that Iowa represented a large range extension for this species, label data were collected to update its range. Numerous insect collections and references were checked and specimens representing 17 states were located

The WIMP capture process for dark stars in the early universe

The first stars to form in the universe may have been dark stars, powered by dark matter annihilation instead of nuclear fusion. The initial amount of dark matter gathered by the star gravitationally can sustain it only for a limited period of time. It has been suggested that capture of additional dark matter from the environment can prolong the dark star phase even to the present day. Here we show that this capture process is ineffective to prolong the life of the first generation of dark stars. We construct a Monte-Carlo simulation that follows each Weakly Interacting Massive Particle (WIMP) in the dark matter halo as its orbit responds to the formation and evolution of the dark star, as it scatters off the star's nuclei, and as it annihilates inside the star. A rapid depletion of the WIMPs on orbits that cross the star causes the demise of the first generation of dark stars. We suggest that a second generation of dark stars may in principle survive much longer through capture. We comment on the effect of relaxing our assumptions.Comment: 13 pages, 6 figure

Review of Observational Evidence for Dark Matter in the Universe and in upcoming searches for Dark Stars

Over the past decade, a consensus picture has emerged in which roughly a quarter of the universe consists of dark matter. The observational evidence for the existence of dark matter is reviewed: rotation curves of galaxies, weak lensing measurements, hot gas in clusters, primordial nucleosynthesis and microwave background experiments. In addition, a new line of research on Dark Stars is presented, which suggests that the first stars to exist in the universe were powered by dark matter heating rather than by fusion: the observational possibilities of discovering dark matter in this way are discussed.Comment: 14 pages, 7 figures, Conference Proceeding for "Dark Matter and Dark Energy" in Lyon, France, July 200

Primordial Non-Gaussian Signatures in the Sky

The presence of non-Gaussian features in the CMB radiation maps represents one of the most long-awaited clues in the search for the actual structure of the primordial radiation. These features could shed some light on the non trivial task of distinguishing the real source of the primeval perturbations leading to large scale structure. In the present paper we briefly review recent work towards finding analytical estimates of the three- and four-point correlation functions and of their zero-lag limits, namely, the skewness and kurtosis, respectively. - Contributed talk to appear in the proceedings of "Birth of the Universe & Fundamental Physics", May 18-21, 1994, Rome, Italy.Comment: 4pp; PostScript fil

Instability and Subsequent Evolution of Electroweak Bubbles

Bubbles in a first-order electroweak phase transition are nucleated with radii $R_0$ and expand with velocity $v$. If $v$ is subsonic, a bubble becomes unstable to non-spherical perturbations when its radius is roughly $10^4\, R_0$. These perturbations accelerate the transition, and the effective velocity of bubble growth rapidly becomes supersonic. The transition should subsequently proceed spherically via detonation. If for some reason the onset of detonation is postponed, the surface area of the bubbles may be enhanced by $10^5$. We discuss consequences for electroweak baryogenesis.Comment: 9 pages (IASSNS-HEP-92-46

Optical disks become erasable

The topics covered include the following: optical recording; how does it work?; why all the fuss?; state of the industry; sample applications; and future directions