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Some new results concerning the QFT vacuum in the Heisenberg picture

Dan Solomon
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Abstract

In has been recently shown [1] that in Dirac's hole theory the vacuum state is not the minimum energy state but that there exist quantum states with less energy than that of the vacuum state. In this paper we extend this discussion to quantum field theory (QFT) and consider the question of whether or not the vacuum in QFT is the state of minimum energy. It will be shown that for a "simple" field theory, consisting of a quantized fermion field interacting with a classical electric field in 1-1D space-time, there exist quauntum states with less energy than that of the vacuum state.

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Dan Solomon. 2008-02-18. Some new results concerning the QFT vacuum in the Heisenberg picture. https://arxiv.org/abs/quant-ph/0701022

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