 |
||
|
|
| Post Doctoral Research |
|
|
BCCP Fellows
Hee-Jong Seo
My research interests are in high precision cosmology with large scale structure. I have studied analytically and numerically the performance of the BAO in large galaxy surveys as a dark energy probe. I also worked on the evolution of galaxy clustering and halo occupation distribution, using dissipationless N-body simulations. My recent research have aimed at extending my previous work as well as expanding to observational and experimental studies and to weak lensing study: I have worked on nonlinear effects on BAO in depth with various high-resolution simulations, the effect of galaxy bias and redshift distortions on BAO, a feasibility of a BAO survey in radio bands, and combining BAO with SN data from SDSS. The ongoing projects are 1. measuring the power spectrum of cosmic shear from SDSS Stripe 82 2. re-capturing more cosmic information by Gaussianizing the convergence field 3. deriving a BAO constraint from the SDSS III imaging data. Lawrence Berkeley National Laboratory
Tristan Smith
My research lies at the interface between cosmology and gravity. Gravity has always occupied a unique place among the fundamental forces of nature: as the 'universal force' it plays an essential role in the evolution of the Universe, from the big bang to today; as the only known force that cannot be written within a consistent quantum theory its underlying nature is expected to help elucidate the complete 'theory of everything'; as the weakest force it allows information to come to us to from events occurring at energy scales approaching the Planck scale. My research concentrates on using novel probes in order to address questions concerning the dynamics of inflation, the nature of dark energy, observational signatures of string-inspired modifications to general relativity, and the fundamental symmetries of gravity (such as parity and Lorentz invariance). Primordial gravitational-wave backgrounds provide an unparalleled window into physical processes occurring at energy scales as high as the Planck scale. In particular, the gravitational-wave background might allow us to infer fundamental properties of the processes that produce such backgrounds, such as inflation. To this end, along with Marc Kamionkowski and Asantha Cooray, I have studied how the direct detection of the inflationary gravitational-wave background (IGWB) would enable a probe of the fundamental nature of the inflationary epoch. Our work has shown how direct observations of the IGWB will allow us an unprecedented view into the mechanisms behind inflation and that there is a good chance the IGWB will be observable in BBO. However it is possible that a non-standard expansion history could complicate interpretations of the physical significance of the amplitude and slope of the directly observed IGWB. In future research I plan to address these issues and quantify how well we may be able to remove degeneracies with a non-standard expansion history. In addition to this, along with George Smoot and his student Noel Swanson, I have begun a study in order to explore how well we may use pulsar timing arrays in order to detect and measure the properties of gravitational waves. Currently, pulsar timing arrays are the most sensitive probe of gravitational waves and their sensitivity is expected to increase by several orders of magnitude with the construction of the Square Kilometer Array (SKA) radio telescope which plans to be in full operation by 2020. Many groups have explored how to use pulsar timing measurements in order to place limits on stochastic gravitational wave backgrounds. However, less work has focused on identifying how to use this data to explore other sources of gravitational waves such as short duration bursts and polarized backgrounds. We plan to articulate how best to use this data in order to extract as much information about gravitational waves as possible. Read more here. Publications
Lawrence Berkeley National Laboratory
|
|
|
