Kolloquien
Wintersemester 2017/2018
URL zum ICS-Kalender dieses Seminars
Kirchhoff-Institut für Physik, Otto-Haxel-Hörsaal
freitags 17:15
Vorträge
27.10.2017 17:00
KIP, INF 227, Otto-Haxel-Hörsaal
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 diagram of
Type Ia 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, rather surprisingly, that the data are
still quite consistent with a constant rate of expansion. This motivates discussion of the
foundations of the standard cosmological model, in particular whether dark energy
really exists.