Greybody Factors of Charged Dilaton Black Holes in 2 + 1 Dimensions

We have studied scalar perturbations of charged dilaton black holes in 2+1 dimensions. The black hole considered here is a solution to the low-energy string theory in 2+1 dimensions. The exact decay rates and the grey body factors for the massless minimally coupled scalar is computed for both the charged and the uncharged dilaton black holes. The charged and the uncharged black hole show similar behavior for grey body factors, reflection coefficients and decay rates.Comment: The equation for the potential and figure:1 are changed. The changes does not effect the result

SURVEYING POPULATIONS OF RED-BILLED CURASSOWS (CRAX BLUMENBACHII) IN THE ATLANTIC FOREST OF BRAZIL

Threatened species are frequently difficult to monitor, leading to a lack of information for the selection of the best conservation strategies. A case in point is the Red-billed Curassow (Crax blumenbachii, Cracidae, Galliformes), whose populations have declined due to deforestation of the northern Atlantic Forest and increased poaching in the late 1960s. The species is presently absent from most forest frag- ments within its geographic range, occurring only in forest remnants on the states of Bahia and Espírito Santo, Brazil. In this study, we esti- mated encounter rates and recorded the periods of activity of the Red-billed Curassow in three large Atlantic Forest fragments in the north- eastern Brazilian state of Bahia, using line-transect sampling. The northern region of Serra do Conduru State Park (0.29 sighting/10 km) and Descobrimento National Park (0.27 sighting/10 km) presented slightly greater encounter rates of this endangered cracid, compared to the Una Biological Reserve (0.13 – 0.20 sighting/10 km). We recorded Red-billed Curassows throughout the day, mainly between 10:00–11:00 h and 14:00–17:00 h. Our study is the first step for long-term monitoring of the Red-billed Curassow. These findings serve as baseline infor- mation, which may contribute to future assessments of the conservation status and support future conservation actions for the species

Non-local charges on AdS_5 x S^5 and PP-waves

We show the existence of an infinite set of non-local classically conserved charges on the Green-Schwarz closed superstring in a pp-wave background. We find that these charges agree with the Penrose limit of non-local classically conserved charges recently found for the $AdS_5 \times S^5$ Green-Schwarz superstring. The charges constructed in this paper could help to understand the role played by these on the full $AdS_5 \times S^5$ background.Comment: 20 pages. JHEP. v2:references adde

Distribution of Energy-Momentum in a Schwarzschild-Quintessence Space-time Geometry

An analysis of the energy-momentum localization for a four-dimensional\break Schwarzschild black hole surrounded by quintessence is presented in order to provide expressions for the distributions of energy and momentum. The calculations are performed by using the Landau-Lifshitz and Weinberg energy-momentum complexes. It is shown that all the momenta vanish, while the expression for the energy depends on the mass $M$ of the black hole, the state parameter $w_{q}$ and the normalization factor $c$. The special case of $w_{q}=-2/3$ is also studied, and two limiting cases are examined.Comment: 9 page

Metastable SUSY Breaking, de Sitter Moduli Stabilisation and K\"ahler Moduli Inflation

We study the influence of anomalous U(1) symmetries and their associated D-terms on the vacuum structure of global field theories once they are coupled to N=1 supergravity and in the context of string compactifications with moduli stabilisation. In particular, we focus on a IIB string motivated construction of the ISS scenario and examine the influence of one additional U(1) symmetry on the vacuum structure. We point out that in the simplest one-Kahler modulus compactification, the original ISS vacuum gets generically destabilised by a runaway behaviour of the potential in the modulus direction. In more general compactifications with several Kahler moduli, we find a novel realisation of the LARGE volume scenario with D-term uplifting to de Sitter space and both D-term and F-term supersymmetry breaking. The structure of soft supersymmetry breaking terms is determined in the preferred scenario where the standard model cycle is not stabilised non-perturbatively and found to be flavour universal. Our scenario also provides a purely supersymmetric realisation of Kahler moduli (blow-up and fibre) inflation, with similar observational properties as the original proposals but without the need to include an extra (non-SUSY) uplifting term.Comment: 38 pages, 8 figures. v2: references added, minor correction

Large-Volume Flux Compactifications: Moduli Spectrum and D3/D7 Soft Supersymmetry Breaking

We present an explicit calculation of the spectrum of a general class of string models, corresponding to Calabi-Yau flux compactifications with h_{1,2}>h_{1,1}>1 with leading perturbative and non-perturbative corrections, in which all geometric moduli are stabilised as in hep-th/0502058. The volume is exponentially large, leading to a range of string scales from the Planck mass to the TeV scale, realising for the first time the large extra dimensions scenario in string theory. We provide a general analysis of the relevance of perturbative and non-perturbative effects and the regime of validity of the effective field theory. We compute the spectrum in the moduli sector finding a hierarchy of masses depending on inverse powers of the volume. We also compute soft supersymmetry breaking terms for particles living on D3 and D7 branes. We find a hierarchy of soft terms corresponding to `volume dominated' F-term supersymmetry breaking. F-terms for Kahler moduli dominate both those for dilaton and complex structure moduli and D-terms or other de Sitter lifting terms. This is the first class of string models in which soft supersymmetry breaking terms are computed after fixing all geometric moduli. We outline several possible applications of our results, both for cosmology and phenomenology and point out the differences with the less generic KKLT vacua.Comment: 64 pages, 4 figures; v2. references added; v3. typos, reference added, matches published versio

de Sitter String Vacua from Supersymmetric D-terms

We propose a new mechanism for obtaining de Sitter vacua in type IIB string theory compactified on (orientifolded) Calabi-Yau manifolds similar to those recently studied by Kachru, Kallosh, Linde and Trivedi (KKLT). dS vacuum appears in KKLT model after uplifting an AdS vacuum by adding an anti-D3-brane, which explicitly breaks supersymmetry. We accomplish the same goal by adding fluxes of gauge fields within the D7-branes, which induce a D-term potential in the effective 4D action. In this way we obtain dS space as a spontaneously broken vacuum from a purely supersymmetric 4D action. We argue that our approach can be directly extended to heterotic string vacua, with the dilaton potential obtained from a combination of gaugino condensation and the D-terms generated by anomalous U(1) gauge groups.Comment: 17 pages, 1 figur

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results