Fredagskollokvium: Testing dark energy models with atom interferometry

Dr. Clare Burrage, University of Nottingham (UK).

Tid og sted: 11. sep. 2020 11:00 – 12:00, Rom 304 (Peisestua), Institutt for teoretisk astrofysikk

Dr. Clare Burrage, School of Physics and Astronomy Particle Theory Group, University of Nottingham (UK).

Foto: C. Burrage

The accelerated expansion of the universe motivates a wide class of scalar field theories that modify gravity on large scales. In regions where the General Relativity has been confirmed by experiment, such theories need a screening mechanism to suppress the new force. I will describe how theories with screening mechanisms can be tested in the laboratory, in particular with atom-interferometry experiments.
I will describe the results of a recent experiment in which we measured the acceleration of an atom toward a macroscopic test mass inside a high vacuum chamber, where the new force is unscreened in some theories. Our measurement shows that the attraction between atoms and the test mass does not differ appreciably from Newtonian gravity. This result places stringent limits on the free parameters in chameleon and symmetron theories of modified gravity.

Pisa tower — Pisa experiment by Galileo Galiei. In 1589, so the story goes, the Italian scientist Galileo Galilei took two cannon balls of different weight to the top of the Tower of Pisa and dropped them off the side. Both balls landed at the same time. This showed that the weight of an object does not change how fast it falls - heavy objects do not fall faster than light ones. Image credit:Image credits: Theresa Knott.

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Publisert 20. nov. 2019 19:06 - Sist endret 9. sep. 2020 14:24