3 papers
quant-ph2025
Ghost-Free Quantisation of Higher Time-Derivative Theories via Non-Unitary Similarity Transformations
Andreas Fring, Takano Taira, Bethan Turner
We address the long-standing ``ghost problem" in higher time-derivative theories (HTDTs), where quantisation typically yields sectors with either unbounded spectra or non-normalisa…
quant-ph2025
Exact treatment of the memory kernel under time-dependent system-environment coupling via a train of delta distributions
Yuta Uenaga, Kensuke Gallock-Yoshimura, Takano Taira
Memory effects in a quantum system coupled to an environment are one of the central features in the theory of open quantum systems. The dynamics of such quantum systems are typical…
hep-th2021
Non-Hermitian gauge field theories and BPS limits
Andreas Fring, Takanobu Taira
We present an overview of some key results obtained in a recent series devoted to non-Hermitian quantum field theories for which we systematically modify the underlying symmetries.…