 Cosmological 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
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.
Some interesting links
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