JRG - Junior Research Groups
The observational cosmology group extracts statistical information from combinations of large scale structure, Cosmic Microwave Background temperature fluctuations and astrophysical distance measurements, then uses the data to place constraints on the evolution, initial conditions and energy contents of the Universe. Current state-of-the-art cosmological data are increasingly pointing towards tension in the standard cosmological model -- local and cosmological distance measurements are discrepant, violations of statistical isotropy have been detected in the matter fluctuations. These trends suggest that the standard model may require significant modification. The observational cosmology group are applying innovative statistical techniques to the latest galaxy catalogs, and testing both the standard model and the underlying assumptions that are made during the process of cosmological data reduction.
In tandem, the group is studying spherically symmetric spacetime metrics for scalar-tensor dark energy models, the intrinsic alignment of galaxies at high redshift, the topology of random fields, statistical violations of isotropy of finite volume random fields and the matter distribution in the local Universe. Our research lies at the intersection of theoretical, observational and numerical cosmology and we are continually seeking to apply our methodologies to other branches of physics.
Professor Stephen Appleby is the head of the \'Observational Cosmology\' research group, established in 2020. He received his Masters in Mathematics and Physics from the University of Manchester (UK) in 2001, and his PhD from Jodrell Bank center for astrophysics/University of Manchester in 2005 as a student of Professor Richard Battye. He held postdoctoral research posts at the Excellence Cluster Universe (Munich), the Institute for the Early Universe (Ewha Womans University, Seoul), Asia Pacific Center for Theoretical Physics (Pohang, Korea), and the Korea Institute for Advanced Study (KIAS, Seoul) prior to forming the observational cosmology group. He concurrently leads a research project on cosmological distance measurements funded by the National Research Foundation of Korea.
Cosmological Parameter Estimation from the Two-dimensional Genus Topology—Measuring the Expansion History Using the Genus Amplitude as a Standard Ruler
The Well-Tempered Cosmological Constant: Fugue in B flat
First Evidence of Intrinsic Alignments of Red Galaxies at z>1Cross–correlation between CFHTLenS and FastSound Sample
Minkowski Functionals of SDSS-III BOSS Hints of Possible Anisotropy in the Density Field