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The strength of small-instanton amplitudes in gauge theories with compact extra dimensions

E. Poppitz·Y. Shirman
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Abstract

We study instanton effects in theories with compact extra dimensions. We perform an instanton calculation in a 5d theory on a circle of radius R, with gauge, scalar, and fermion fields in the bulk of the extra dimension. We show that, depending on the matter content, instantons of size rho << R can dominate the amplitude. Using deconstruction as an ultraviolet definition of the theory allows us to show, in a controlled approximation, that for a small number of bulk fermions, the amplitude for small size instantons exponentially grows as e^{O(1)R/rho}.

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E. Poppitz, Y. Shirman. 2002-07-25. The strength of small-instanton amplitudes in gauge theories with compact extra dimensions. https://doi.org/10.1088/1126-6708%2F2002%2F07%2F041

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