The Accelerating Universe: Landscape or Modified Gravity?

Recording Details

Speaker(s): 
Scientific Areas: 
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PIRSA Number: 
08020046

Abstract

The most remarkable recent discovery in fundamental physics is that the Universe is undergoing accelerated expansion. A proper understanding of its physical origin forces us to make a hard choice between dynamical and environmental scenarios. The former approach predicts the existence of a new long distance physics in the gravitational sector, while the second relies on the vast landscape of vacua with different values of the cosmological constant. I will discuss achievements and shortcomings of both approaches, and illustrate them in the concrete examples.