Скачать с ютуб QsimFP Seminar Ian Spielman on Hubble in Expanding and Contracting Cold-Atom Universes в хорошем качестве

QsimFP Seminar Ian Spielman on Hubble in Expanding and Contracting Cold-Atom Universes

Register to our seminar mailing list here: https://forms.gle/4meJfSGnGeeoywTR8 QSimFP Seminar (FVD): Accurate Determination of Hubble Attenuation and Amplification in Expanding and Contracting Cold-Atom Universes by Ian Spielman (NIST: National Institute of Standards and Technology, US Dept of Commerce) (Recorded on 7 March 2023 - Bio & Abstract below) The Quantum Simulator for Fundamental Physics (QSimFP) consortium, including 15 investigators from 7 UK Research Organisations and 5 International Partners was formed in 2018-2020. Funding through the Quantum Technology for Fundamental Physics initiative started in November 2020 with the project duration of 3 years and 5 months. Our programme unites the quantum-technology and fundamental-physics communities, with leading scientists from both camps now working together and focusing on common goals. https://qsimfp.org/ BIO AND ABSTRACT Abstract: In the expanding universe, relativistic scalar fields are thought to be attenuated by “Hubble friction,” which results from the dilation of the underlying spacetime metric. By contrast, in a contracting universe this pseudofriction would lead to amplification. Here, we experimentally measure, with fivefold better accuracy, both Hubble attenuation and amplification in expanding and contracting toroidally shaped Bose-Einstein condensates, in which phonons are analogous to cosmological scalar fields. We find that the observed attenuation or amplification depends on the temporal phase of the phonon field, which is only possible for nonadiabatic dynamics. References: [1] Accurate Determination of Hubble Attenuation and Amplification in Expanding and Contracting Cold-Atom Universes; S. Banik, M. G. Galan, H. Sosa-Martinez, M. Anderson, S. Eckel, I. B. Spielman, and G. K. Campbell; Phys. Rev. Lett. 128 090401 (2022). doi:10.1103/PhysRevLett.128.090401 [2] A Rapidly Expanding Bose-Einstein Condensate: An Expanding Universe in the Lab; S. Eckel, A. Kumar, T. Jacobson, I. B. Spielman, and G. K. Campbell; Phys. Rev. X 8 21021 (2018). doi:10.1103/PhysRevX.8.021021 Ian Spielman is a fellow at the Joint Quantum Institute, National Institute of Standards and Technology and the University of Maryland.