Related papers: String amplitudes and the Penrose limit

This paper was withdrawn by the author. It turns out that similar ideas have been presented before. The author apologizes.

This paper has been withdrawn by the author because the conclusions reached in it are incorrect.

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This paper has been withdrawn by the author due to an error made in the analysis of MHV amplitudes with external fundamental matter fields in the superconformal N=2 SQCD.

This paper has been temporarily withdrawn by the author because there are errors in it that require further study.

This paper has been withdrawn by the authors, due a crucial error in Sec. 3.

This paper has been withdrawn by the author due to rewritting and skipping crucial sign errors.

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The original version of this paper contains an error; when this is corrected the basic conclusion changes. A revised manuscript will be submitted shortly.

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This paper has been withdrawn by the author due to an error.

This paper has been withdrawn by the authors due to a gap in the proof of the main result (in 5.3).

This paper has been withdrawn by the author due to rewritting and skipping crucial sign errors.

This paper has been withdrawn by the author due to a crucial errors.

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This paper has been withdrawn by the author due to imprecisions which must conduce to wrong results.

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