DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS
HIP seminar room A315
- Tuesday 6 March 2018 at 10.15 in A315: Kenneth Österberg (Helsinki)
- Tuesday 8 May 2018 at 10.15 in A315: Tommi Markkanen (Imperial College, London)
Evaporation of de Sitter space
Abstract: The exponentially expanding de Sitter solution is frequently encountered in cosmology due to its significance for the late and early Universe. However, its stability in a quantised theory has for a long time been the source of debate. In this talk we discuss this issue in the framework of semi-classical gravity. Based on a first principle calculation, I argue that when one considers the experiences of a local observer, the quantum back reaction destabilizes de Sitter space leading to a gradual continuous increase of the dS horizon. This implies that the cosmological ‘constant’ decays over time, with flat space as the asymptotic late time solution.
- Tuesday 7 August 2018 at 10.15 in A315: Mikko Laine (Bern)
Hopefully the up to 50 min + 10 min discussion long seminar/colloquium will be understandable to a wide audience.
Contacts: Keijo Kajantie (keijo kajantie at helsinki fi) [department / HIP seminar],
Francesco Montanari (francesco montanari at helsinki fi) [cosmo seminar]
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