https://en.wikipedia.org/wiki/Multiple_time_dimensions#Physics https://en.wikipedia.org/wiki/Multiple_time_dimensions#Physi... https://arxiv.org/abs/hep-th/910

https://en.wikipedia.org/wiki/Multiple_time_dimensions#Physics https://en.wikipedia.org/wiki/Multiple_time_dimensions#Physi... https://arxiv.org/abs/hep-th/9109030 https://arxiv.org/abs/hep-th/9109030