Current Research Interests
My main area of research
is weak gravitational lensing, the very small perturbations in
the shapes of distant source galaxies due to massive foreground
galaxies/clusters. There are many useful applications of weak lensing due to
the fact that it is sensitive to the full matter density projected
along the line of sight, regardless of whether that matter is luminous
(i.e., visible through a telescope) or not (the mysterious dark matter). I am
interested in applications of lensing both to the study of large-scale
structure and to galaxy formation, and also using lensing to answer
these questions in combination with other
probes such as clustering measures.
Some past projects that have used lensing to address a variety of
topics include:
- Measuring galaxy halo masses and satellite fractions as a
function of optical observables such as galaxy morphology, luminosity,
and stellar mass.
- Constraints on cosmological parameters from the relationship
between galaxy bias (measured using clustering) and halo mass
(measured using lensing).
- Measuring density profiles of luminous red galaxies, for
comparison with the predictions for the dark matter profiles from
cosmological N-body simulations.
On my publications page, there are links to the publications that
resulted from these projects.
Some ongoing projects include:
Combining clustering (galaxy-galaxy autocorrelations) and
galaxy-galaxy lensing (galaxy-mass cross-correlations) to constrain
cosmological parameters.
With Gary Bernstein, Reiko Nakajima, and many others, a survey of
the twenty most massive clusters at moderate redshifts in the northern
hemisphere, comparing their X-ray, optical, and dark matter
distributions (from lensing) to constrain N-body + hydrodynamics
models of cluster formation and evaluate prospects for future
cluster-count cosmology.
Participating in the planning of a weak lensing survey with
Hyper-SuprimeCam (HSC) on the Subaru telescope.
In the future, I plan to continue with lensing, hopefully with some of
the surveys that are being planned for the next decade or so, while
expanding my interests to include other probes of cosmology and galaxy
formation/evolution.
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