The accelerated expansion of the universe hints at the existence of a new light degree of freedom in the gravitational sector.  Such a degree of freedom, generally taken to be a scalar, mediates a fifth force between matter particles.  This property is in tension with existing tests of gravity, unless the fifth force is screened, i.e. it dynamically weakens in certain environments.  A new generation of gravitational experiments, being performed in the laboratory, are designed to be sensitive to screened forces, and have made great headway towards detecting or ruling out screened forces over the past several years.  In this talk I will focus on how atom interferometry in particular has resulted in strong new bounds on one of the simplest and most popular models of screened modified gravity, the chameleon.

 

Zoom meeting ID:  999 3023 4812
For the password to access the meeting please contact one of us:
Kurt Hinterbichler: kjh92
Alexis Plascencia: adp110
Ellen Rabe: exr223
Idit Zehavi: ixz6
at case.edu