Frequency spectrum of an optical resonator in a curved spacetime

Funding

We thank Ralf Menzel, Jonas Schmöle, Tobias Westphal, Philipp Haslinger, José Natário, Luis Cortés Barbado, Jan Kohlrus, Ana Lucía Baez and Uwe R Fischer for interesting remarks and discussions and Kiri Mochrie for writing assistance. DR thanks the Humboldt Foundation for funding his research in Vienna with their Feodor-Lynen Felloship. RH and IF would like to acknowledge that this project was made possible through the support of the grant ‘Leaps in cosmology: gravitational wave detection with quantum systems’ (No. 58745) from the John Templeton Foundation. The opinions expressed in this publication are those of the authors and do not necessarily reflect the views of the John Templeton Foundation. IF would like to acknowledge that this project was made possible through the support of the grant ‘Quantum Observers in a Relativistic World’ from FQXi’s Physics of the Observer program. The authors thank José Ignacio Latorre and the Centro de Ciencias de Benasque Pedro Pascual for hosting the workshop ‘Gravity in the Lab’ in 2016 where the collaboration started that led to this article. The publication of this article is funded by the Open Access Publishing Fund of the University of Vienna.