1,589 research outputs found
Lagrangian Insertion in the Light-Like Limit and the Super-Correlators/Super-Amplitudes Duality
In these notes we describe how to formulate the Lagrangian insertion
technique in a way that mimics generalized unitarity. We introduce a notion of
cuts in real space and show that the cuts of the correlators in the
super-correlators/super-amplitudes duality correspond to generalized unitarity
cuts of the equivalent amplitudes. The cuts consist of correlation functions of
operators in the chiral part of the stress-tensor multiplet as well as other
half-BPS operators. We will also discuss the application of the method to other
correlators as well as non-planar contributions.Comment: 25 pages, 9 figures, added references; some sections have been
expanded, a substantial part have been rearranged; v4 examples added to make
it easier to rea
Viscous computations of cold air/air flow around scramjet nozzle afterbody
The flow field in and around the nozzle afterbody section of a hypersonic vehicle was computationally simulated. The compressible, Reynolds averaged, Navier Stokes equations were solved by an implicit, finite volume, characteristic based method. The computational grids were adapted to the flow as the solutions were developing in order to improve the accuracy. The exhaust gases were assumed to be cold. The computational results were obtained for the two dimensional longitudinal plane located at the half span of the internal portion of the nozzle for over expanded and under expanded conditions. Another set of results were obtained, where the three dimensional simulations were performed for a half span nozzle. The surface pressures were successfully compared with the data obtained from the wind tunnel tests. The results help in understanding this complex flow field and, in turn, should help the design of the nozzle afterbody section
Gravitino Interactions from Yang-Mills Theory
We fabricate gravitino vertex interactions using as only input on-shell
Yang-Mills amplitudes and the Kawai-Lewellen-Tye gauge theory / gravity
relations. A useful result of this analysis is simpler tree-level Feynman rules
for gravitino scattering than in traditional gauges. All results are explicitly
verified until five point scattering.Comment: 17 pages, 10 figures, REVTe
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