22,552 research outputs found
Exact treatment of states
Using the basic ingredient of supersymmetry, a general procedure for the
treatment of quantum states having nonzero angular momenta is presented.Comment: 7 pages article in LaTEX (uses standard article.sty). No Figures.
Accepted by Chinese Physics Letters (2004, vol 21. No.9
Classical {\it vs.}\ Landau-Ginzburg Geometry of Compactification
We consider superstring compactifications where both the classical
description, in terms of a Calabi-Yau manifold, and also the quantum theory is
known in terms of a Landau-Ginzburg orbifold model. In particular, we study
(smooth) Calabi-Yau examples in which there are obstructions to parametrizing
all of the complex structure cohomology by polynomial deformations thus
requiring the analysis based on exact and spectral sequences. General arguments
ensure that the Landau-Ginzburg chiral ring copes with such a situation by
having a nontrivial contribution from twisted sectors. Beyond the expected
final agreement between the mathematical and physical approaches, we find a
direct correspondence between the analysis of each, thus giving a more complete
mathematical understanding of twisted sectors. Furthermore, this approach shows
that physical reasoning based upon spectral flow arguments for determining the
spectrum of Landau-Ginzburg orbifold models finds direct mathematical
justification in Koszul complex calculations and also that careful point- field
analysis continues to recover suprisingly much of the stringy features.Comment: 14
Design and fabrication of Rene 41 advanced structural panels
The efficiency was investigated of curved elements in the design of lightweight structural panels under combined loads of axial compression, inplane shear, and bending. The application is described of technology generated in the initial aluminum program to the design and fabrication of Rene 41 panels for subsequent performance tests at elevated temperature. Optimum designs for two panel configurations are presented. The designs are applicable to hypersonic airplane wing structure, and are designed specifically for testing at elevated temperature in the hypersonic wing test structure located at the NASA Flight Research Center. Fabrication methods developed to produce the Rene panels are described, and test results of smaller structural element specimens are presented to verify the design and fabrication methods used. Predicted strengths of the panels under several proposed elevated temperature test load conditions are presented
An investigation of the use of Faraday rotation for the measurement of magnetic fields
Potential use of Faraday rotation and Kerr magnetooptical effect for magnetic field measurement
Investigation of the use of the Kerr magneto-optic effect for the measurement of magnetic fields, phase 2 Final report
Use of Kerr magnetooptical for measuring magnetic field
"So what will you do if string theory is wrong?"
I briefly discuss the accomplishments of string theory that would survive a
complete falsification of the theory as a model of nature and argue the
possibility that such a survival may necessarily mean that string theory would
become its own discipline, independently of both physics and mathematics
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