A Brief Description of My Research Program
Cosmology is entering a golden age where exciting new ideas interact
with technologically innovative observations. The age is marked in
particular by rapid progress in our observational knowledge of the
large--scale structure of the Universe and in our theoretical
understanding of the evolution of this large--scale structure from its
probable quantum mechanical origin in the first fractions of a second
of the big bang. This theoretical understanding includes physics that
is beyond the particle physicist's (otherwise) succesful standard
model.
The past decade has seen the establishment of a basic paradigm for the
formation of structure in the Universe. The Universe used to be
highly homogeneous, with spatial variations in the density no larger
than about 1 part in a hundred thousand. Over time these initial
perturbations grew by gravitational instability (denser regions
attracted more matter, growing even denser, attracting even more
matter...) to become the diversity of structures we see in the
Universe today such as stars, galaxies and galaxy clusters. The
success of such a simple picture provides encouragement that we are on
the right track. Future observational and theoretical advances
will allow for a more thorough understanding of the evolution of
structure and provide insight into the fundamental laws of physics.
Fortunately for the active researcher, the challenges that remain are
varied and formidable. Despite the progress of the past decade there
are many questions left unanswered, and many that were answered have
led to new ones. What is this weakly interacting dark matter that
appears to be the dominant form of matter in the Universe? What is
the nature of the 'dark energy'? Why is the expansion rate
accelerating now? What is the origin of the tiny deviations from
homogeneity that were the initial seeds of structure in the Universe?
Other pressing questions are: What are the observable signatures of
answers to the above questions? How can we best exploit available
technology to shed light on them? How can we optimally make use of
the tremendous amounts of data that are now and will be available?
Does a global analysis of all available data reveal any
inconsistencies in our models. Are these inconsistencies
due to systematic error in the data, or must we rethink the
basic paradigm?
I look for opportunities to address all of the above questions. Most
of my time now and in the near future is spent on what I call
"cosmological phenomenology"; that is, predicting observables,
developing methods for exploiting data, and deriving the theoretical
implications of data. I expect this emphasis to continue to be
rewarding given the quantity and quality of data which we expect
to be generated by planned observational missions.
Further Information: