Theory HEP Seminar

Backreaction as an alternative to dark energy and modified gravity

Syksy Rasanen

CERN

Cosmological observations are usually thought to imply the existence of dark energy or modified gravity. However, it may be possible to explain late-time observations simply by taking into account the influence of non-linear structures on the expansion rate and light propagation. I explain the physics involved and present a semi-realistic model where the observed timescale of about 10 billion years emerges from structure formation.