Fredagskollokvium: Modified gravity and CMB observables
Carsten van de Bruck, Professor, University of Sheffield
Modifications of gravity can leave an imprint on the cosmic microwave background radiation (CMB). This can either be due to new fifth forces mediated by a dark energy scalar field or new interactions coming from the time-evolution of dark energy or its spatial gradients. I will review how the CMB can be used to test modification of gravity. Both so-called conformal couplings and disformal couplings of a scalar field to other energy forms will be introduced and discussed.