Over the last decade or so, observations of a number of features present in our Universe have led to a growing consensus that on large scales at least the Universe is pretty simple to understand.
It looks to be well described by General Relativity, very uniform with structures being seeded from gravitational instability whose origin resides somewhere in the earliest moments of the Universe’s evolution. The energy content appears to be made up of baryons (~5%), cold dark matter (~25%) and dark energy (~70%), and everything seems to be consistent with the Universe being spatially flat and having an origin some 13.8 billion years ago.
But when we delve a bit deeper there appear to be a number of features we actually don’t understand. What is the dark matter made of, what is the dark energy that is driving the Universe into a period of acceleration and what were the origins of the seed fluctuations from which all structures emerged?
Inflation seems to be the favourite candidate for the latter, but where does inflation reside in particle physics? It seems pretty hard to incorporate in models of the early Universe.
In this talk we will revisit some of the exciting recent data to address a number of these questions and also ask whether we are barking up the wrong tree. Maybe we are seeing the first evidence of modifications of General Relativity on large scales – if we are how can we test for it?
Free.
Talk by Prof Edmund Copeland, University of Nottingham. This talk is supported by Exeter College.
