Nikhef Colloquium: "Is there evidence for cosmic acceleration?" (Prof. Subir Sarkar)
Friday, 24 March 2017 -
11:15
Monday, 20 March 2017
Tuesday, 21 March 2017
Wednesday, 22 March 2017
Thursday, 23 March 2017
Friday, 24 March 2017
11:15
Is there evidence for cosmic acceleration?
-
Subir Sarkar
(
Niels Bohr Institute
)
Is there evidence for cosmic acceleration?
Subir Sarkar
(
Niels Bohr Institute
)
11:15 - 12:05
Room: Z011
Abstract: The ‘standard’ model of cosmology is founded on the basis that the expansion rate of the universe is accelerating at present – as was inferred from the Hubble disgram of Type la supernovae. There exists now a much bigger database of supernovae so we can perform rigorous statistical tests to check whether these ‘standardisable candles’ indeed indicate cosmic acceleration. Taking account of the empirical procedure by which corrections are made to their absolute magnitudes to allow for the varying shape of the light curve and extinction by dust, we find that the data are still consistent with a constant rate of expansion. This motivates discussion of whether dark energy really exists. This colloquium is part of the "Landelijk Seminarium @ Nikhef/CWI, Z011"