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Durham University

Institute of Advanced Study

Past Events

CANCELLED IAS Fellows' Seminar - Why is 95% of the Universe dark? Promises and challenges by the upcoming data deluge

16th March 2020, 13:00 to 14:00, Seminar Room, Institute of Advanced Study, Professor Nelson Padilla (Pontifical Catholic University of Chile)

Abstract

Unfortuantely, due to the covid-19 outbreak we have had to cancel this seminar. We are sorry for any inconvenience or dissapointment caused.

Since ordinary matter cools by emitting radiation we can use ground and space based observations to measure how much ordinary matter there is out there in the Universe. According to our current theory of gravity, General Relativity, there should be more matter in the Universe than we can detect with these observations. This extra invisible matter - which "does not cool" - is termed dark matter. On the other hand, the expansion of the Universe is accelerating. Matter tends to slow down the expansion due to the effect of its attractive gravity; in order to explain the acceleration one needs to include dark energy, a type of energy that can produce a repulsive force. Current work in Cosmology consists in trying to find out what mix of ordinary matter, dark matter and dark energy best explains our data. Upcoming surveys will be so large that it will be possible to study not just the mix, but also the very nature of the dark sector. What is dark matter itself? What about dark energy? Is the latter really needed as a component of the Universe or is the accelerated expansion due to a failure of General Relativity at the very largest scales? We will be able to ask these questions. But there is a problem; the amount of data will be so large that, for the first time, it will be challenging to make model predictions that are more accurate than the noise in the data itself. Failure to achieve this could lead to confuse modelling errors with nature.

Places are limited and so any academic colleagues or students interested in attending a seminar should register online in advance to reserve a place. Places will be confirmed within 48 hours of receipt (subject to availability). Alternatively please contact the Institute in advance to reserve a place.

Contact enquiries.ias@durham.ac.uk for more information about this event.