Holger Müller - Atom interferometers measuring the fine structure constant and probing the dark sector

Prof Holger Müller, University of California at Berkeley, USA

Abstract:

With new technologies, atom interferometers have become instruments for measurements accross physics at 10^-10 sensitivity [1]. For example, we are now close to reporting a new measurement of the fine structure constant alpha with an anticipated accuracy of 2.5x10^-10, allowing for ultra-precise tests of the standard model. 
 
Chameleons are flexible models for dark energy. They become unmeasurably short-ranged in the presence of bulk matter but can now be probed in our cavity-based atom interferometer [2]. We rule out chameleons and a range of other dark energy candidates that would reproduce the observed cosmic acceleration [3]. With upgrades, we may sense any chameleons and a wide class of other exotic models for dark energy and dark matter, such as B-L bosons or f(R) gravity. 
 
[1] Phys. Rev. Lett. 115, 083002 (2015), 
[2] Phys. Rev. Lett. 114, 100405 (2015). 
[3] Science 349, 849 (2015).

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