On the quantisation of complex higher derivative theories and avoiding the Ostrogradsky ghost
On the quantisation of complex higher derivative theories and avoiding the Ostrogradsky ghost
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关于复杂高阶导数理论的量化和避免奥斯特罗格拉茨基幽灵
DOI:
10.1016/j.nuclphysb.2017.01.024
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发表时间:
2016
期刊:
影响因子:
--
通讯作者:
H. Veermae
中科院分区:
文献类型:
--
作者:
M. Raidal;H. Veermae
Generic higher derivative theories are believed to be fundamentally unphysical because they contain Ostrogradsky ghosts. We show that within complex classical mechanics it is possible to construct higher derivative theories that circumvent the Ostrogradsky theorem and have a real energy spectrum that is bounded from below. The complex theory can be canonically quantised. The resulting quantum theory does not suffer from the kinetic instability and maintains the usual probabilistic interpretation without violating the correspondence principle. As a proof of concept, we construct a class of stable interacting complex higher derivative theories and present a concrete example. This consistent and canonical framework allows us to analyse the previous attempts to avoid ghosts that use non-canonical quantisation schemes, such as the Lee–Wick theories, Dirac–Pauli quantisation orPT-symmetric quantum mechanics. The key to understand the would-be ghosts in any kinetically stable higher derivative theory is to accept the complex system behind it.