Higher Spins and Open Strings: Quartic Interactions

We analyze quartic gauge-invariant interactions of massless higher spin fields by using vertex operators constructed in our previous works and computing their four-point amplitudes in superstring theory. The kinematic part of the quartic interactions of the higher spins is determined by the matter structure of their vertex operators;the non-locality of the interactions is the consequence of specific ghost structure of these operators. We compute explicitly the four-point amplitude describing the complete gauge-invariant $1-1-3-3$ quartic interaction (two massless spin 3 particles interacting with two photons) and comment on more general $1-1-s-s$ cases, particularly pointing out the structure of $1-1-5-5$ coupling.Comment: 26 pages, misprints corrected, discussion added in the concluding sectio

Analisis dan Evaluasi Saluran Drainase pada Kawasan Perumnas Talang Kelapa di Sub DAS Lambidaro Kota Palembang

Drainage system is a set of activities that form the effort to drain water whether it is runoff or underground water from an area or region. The purpose for this report is to analyze and evaluate the drainage channels in Perumnas Talang Kelapa Palembang. In the implementation of this report, the short-term rainfall data from 2001 to 2012 was used. The rainfall data was tested according to normal, log normal, log pearson III, and gumbel distribution. Select one result of those distribution with the smallest deviation standard. Then, it must be tested with the smirnov-kolmogorov test to find the rain intensity equation. That equation will be used to find the to plan the drainage dimension. To analyze the incapacitated drainage, this report will use SWMM program. From the amount of 51 conduits in the SWMM model, there are 24 incapacitated conduits. To fix the conduits, the rational method will be used

Gravitational Couplings of Higher Spins from String Theory

We calculate the interaction 3-vertex of two massless spin 3 particles with a graviton using vertex operators for spin 3 fields in open string theory, constructed in our previous work. The massless spin 3 fields are shown to interact with the graviton through the linearized Weyl tensor, reproducing the result by Boulanger, Leclercq and Sundell. This is consistent with the general structure of the non-Abelian $2-s-s$ couplings, implying that the minimal number of space-time derivatives in the interaction vertices of two spin s and one spin 2 particle is equal to $2s-2$.Comment: 19 page

On moduli of vector bundles on p-adic curves and attached representations

In der vorliegenden Arbeit wird das von Deninger/Werner entwickelte p-adische Analogon der klassischen Narasimhan-Seshadri Theorie hinsichtlich der Formulierbarkeit in den Termen der Moduli von Vektorbündeln und entsprechenden Darstellungen untersucht. Sei X eine glatte, projektive und zusammenhängende Kurve über QpBar. Einem Vektorbündel E mit stark semistabiler Reduktion auf X_Cp ordnet das étale Paralleltransport unter anderem eine stetige endlich-dimensionale Darstellung der étalen Fundamentalgruppe von X zu. Andererseits ist jedes Vektorbündel mit stark semistabiler Reduktion ebenfalls semistabil, induziert also einen Cp-wertigen Punkt in dem Modulraum M_X, der semistabile Vektorbündel von entsprechendem Rang und Grad parametrisiert. Es wird gezeigt, dass die Klasse der Vektorbündel auf X_Cp (von festem Rang und Grad), die stark semistabile Reduktion über ZpBar haben, im p-adischen Sinne eine offene Teilmenge in M_X(QpBar) induziert. Desweiteren beschreiben wir die obige Zuordnung der Darstellungen in den Termen der Moduli von Vektorbündeln sowie zugeordneten Darstellungen. Wir zeigen, dass diese unter einer technischen Voraussetzung stetig ist

Perturbations of Dark Solitons

A method for approximating dark soliton solutions of the nonlinear Schrodinger equation under the influence of perturbations is presented. The problem is broken into an inner region, where core of the soliton resides, and an outer region, which evolves independently of the soliton. It is shown that a shelf develops around the soliton which propagates with speed determined by the background intensity. Integral relations obtained from the conservation laws of the nonlinear Schrodinger equation are used to approximate the shape of the shelf. The analysis is developed for both constant and slowly evolving backgrounds. A number of problems are investigated including linear and nonlinear damping type perturbations

World Sheet Logarithmic CFT in AdS Strings, Ghost-Matter Mixing and M-theory

We discuss several closely related concepts in the NSR formulation of superstring theory. We demonstrated that recently proposed NSR model for superstrings on $AdS_5 \times S^5$ is described by the world-sheet logarithmic conformal field theory (LCFT). The origin of LCFT on a world-sheet is closely connected to the matter-ghost mixing in the structure of a brane-like vortex operators. We suggest a dynamical origin of M theory as a string theory with an extra dimension given by bosonised superconformal ghosts.Comment: 20 pages, no figures, harvmac, corrected some typo

Multi-Planet Destabilisation and Escape in Post-Main Sequence Systems

Discoveries of exoplanets orbiting evolved stars motivate critical examinations of the dynamics of $N$-body systems with mass loss. Multi-planet evolved systems are particularly complex because of the mutual interactions between the planets. Here, we study the underlying dynamical mechanisms which can incite planetary escape in two-planet post-main sequence systems. Stellar mass loss alone is unlikely to be rapid and high enough to eject planets at typically-observed separations. However, the combination of mass loss and planet-planet interactions can prompt a shift from stable to chaotic regions of phase space. Consequently, when mass loss ceases, the unstable configuration may cause escape. By assuming a constant stellar mass loss rate, we utilize maps of dynamical stability to illustrate the distribution of regular and chaotic trajectories in phase space. We show that chaos can drive the planets to undergo close encounters, leading to the ejection of one planet. Stellar mass loss can trigger the transition of a planetary system from a stable to chaotic configuration, subsequently causing escape. We find that mass loss non-adiabatically affects planet-planet interaction for the most massive progenitor stars which avoid the supernova stage. For these cases, we present specific examples of planetary escape.Comment: Accepted for publication in MNRAS (2013