Cosmology @ UNSW

ResultsCosmological variability of the Fundamental Constants

The electron to proton mass ratio

The fine structure constant
Modern theories attempting to unify gravity with other interactions (electromagnetism and the strong and weak nuclear forces) consistently require that the fine structure constant vary with time. By analysing high resolution spectra of gas clouds seen in absorption against background quasars, we can constrain any variation over a large percentage of the age of the universe. Our results to date suggest there may be a minute variation!






Cosmology from the Lyman-alpha forest

Simulation of large-scale structure

According to Cold Dark Matter models of large-scale structure formation the Intergalactic Medium at high redshift, observed as QSO absorption lines, is the remnant of the gravitational processes which formed filamentary and sheet-like structures which are so striking in galaxy redshift surveys, such as the 2dF survey.

We have developed a new method to search for large-scale overdensities and underdensities in Lyman-alpha forest absorption spectra. We have applied this technique to the spectra of close group of 10 QSOs and found significant overdensities both along the line of sight and in the plane of the sky.


Cosmology Researchers

Please contact John Webb if you are interested in working on any of these exciting projects.




 

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Jon Everett School of Physics - UNSW 2010