Monthly Meeting December – The Modern Epicycles of Cosmology

Cosmology is in crisis. We know very little about dark energy and dark matter, two things that cosmologists believe
are fundamental to the Universe and integral to the standard model of cosmology. With each new set of high-
precision observation, disagreements between data and the standard model grow. This year experiments like the
DESI survey have cast doubt on the nature of dark energy and how the Universe changed over time. Now the lead-
ing suggestions are that the strength of dark energy changes with time, adding yet more mystery to the phenome-
na. While these new models fit the data, are they true, or are they adding more complexity to a flawed concept? In
this talk we will explore the current landscape of cosmology and question the foundational assumptions of modern
cosmology.

Dr Ryan Ridden is a Rutherford Postdoctoral Research Fellow at the University of Canterbury. His research is fo-
cused in the time domain of astronomy and covers a wide range of topics including supernovae, solar system ob-
jects, exoplanets, active galaxies, and cosmology. Ryan is leading the international Cosmic Cataclysms Collabora-
tion, using space telescope data to search for the fastest explosions and variable objects in the Universe. Earlier this
year Ryan was part of a collaboration which used supernova data to test models of the Universe that did not use
dark energy. Alongside research, Ryan has engaged in public outreach and education, frequently giving public lec-
tures and mentoring future scientists.