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Particles, Astrophysics, and Nuclear Physics Seminar
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Benign vs. Malicious Ghosts in Higher-Derivative Theories
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Andrei
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Smilga
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Universite de Nantes, France
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Interacting theories with higher-derivatives involve ghosts. They correspond to instabilities that display themselves at the classical level. We notice that comparatively “benign” mechanical higher-derivative systems exist, where the classical vacuum is stable with respect to small perturbations and the problems appear only at the nonperturbative level. We argue the existence of benign higher-derivative field theories which are stable with respect to small fluctuations with nonzero momenta. A particular example is the 6D N=2 higher-derivative SYM theory, which is finite and unitary at the perturbative level. The instability with respect to small fluctuations of zero-momentum modes is always present, however. |

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Monday, November 29, 2004
2:00 PM
Gant Science Complex
Physics Department
Room P121
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