Modified gravity from the micron to the megaparsec

Amol Upadhye

January 17, 2013

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Abstract: The observed cosmic acceleration hints at a low-energy modification to General Relativity which could give rise to fifth forces and new particles. After describing f(R), chameleon, and symmetron models, I will discuss constraints on the resulting fifth forces from laboratory torsion pendulum experiments, the stability of stars, and the dynamics of large-scale cosmic structure. In particular, laboratory experiments are on the verge of testing interesting classes of chameleon and symmetron fifth forces. I will also show how new particles predicted by these models, which might be produced through photon interactions in stars or the laboratory, can be used to constrain modifications to gravity.