Velocities as a probe of dark sector interactions (2009)
Koyama, Kazuya, Maartens, Roy, Song, Yong-Seon
Dark energy in General Relativity is typically non-interacting with other matter. However, it is possible that the dark energy interacts with the dark matter, and in this case, the dark matter can...
The Case for Deep, Wide-Field Cosmology (2009)
Scranton, Ryan, Albrecht, Andreas, Caldwell, Robert, Cooray, Asantha, Dore, Olivier, Habib, Salman, ...
Much of the science case for the next generation of deep, wide-field optical/infrared surveys has been driven by the further study of dark energy. This is a laudable goal (and the subject of a...
Temperature and Polarization Spectra (2008)
Ω De, Wayne Hu, Dragan Huterer, Manoj Kaplinghat, Michael Mortonson, Yong-seon Song, ...
reionization TE gravitational waves 10 100 1000 l (multipole) EE BB gravitational lensing Lensing of CMB Fields Gravitational Lensing • Lensing is a surface brightness conserving remapping of...
Testing gravity using weak gravitational lensing and redshift surveys (2008)
Song, Yong-Seon, Doré, Olivier
Using the linear theory of perturbations in General Relativity, we express a set of consistency relations that can be observationally tested with current and future large scale structure surveys. We...
Forecasting Cosmological Constraints from Redshift Surveys (2008)
White, Martin, Song, Yong-Seon, Percival, Will J.
Observations of redshift-space distortions in spectroscopic galaxy surveys offer an attractive method for observing the build-up of cosmological structure, which depends both on the expansion rate of...
Reconstructing the History of Structure Formation using Peculiar Velocities (2008)
Song, Yong-Seon, Percival, Will J.
Measuring the statistics of galaxy peculiar velocities using redshift-space distortions is an excellent way of probing the history of structure formation. In particular, because all galaxies are...
Detectability of a phantom-like braneworld model with the integrated Sachs-Wolfe effect (2008)
Giannantonio, Tommaso, Song, Yong-Seon, Koyama, Kazuya
We study a braneworld model in which a phantom-like behaviour occurs with only cold dark matter and a cosmological constant, due to a large distance modification of gravity. With the addition of...
Consistency test of general relativity from large scale structure of the Universe (2008)
Song, Yong-Seon, Koyama, Kazuya
We construct a consistency test of General Relativity (GR) on cosmological scales. This test enables us to distinguish between the two alternatives to explain the late-time accelerated expansion of...
Large Scale Structure Formation of Normal Branch in DGP Brane World Model (2007)
In this paper, we study the large scale structure formation of the normal branch in DGP model (Dvail, Gabadadze and Porrati brane world model) by applying the scaling method developed by Sawicki,...
Cosmological Constraints on f(R) Acceleration Models (2007)
Song, Yong-Seon, Peiris, Hiranya, Hu, Wayne
Models which accelerate the expansion of the universe through the addition of a function of the Ricci scalar f(R) leave a characteristic signature in the large-scale structure of the universe at the...
The Large Scale Structure of f(R) Gravity (2006)
Song, Yong-Seon, Hu, Wayne, Sawicki, Ignacy
We study the evolution of linear cosmological perturbations in f(R) models of accelerated expansion in the physical frame where the gravitational dynamics are fourth order and the matter is minimally...
Near-Horizon Solution for DGP Perturbations (2006)
Sawicki, Ignacy, Song, Yong-Seon, Hu, Wayne
We develop a scaling ansatz for the master equation in Dvali, Gabadadze, Porrati cosmologies, which allows us to solve the equations of motion for perturbations off the brane during periods when the...
Large-Scale Tests of the DGP Model (2006)
Song, Yong-Seon, Sawicki, Ignacy, Hu, Wayne
The self-accelerating braneworld model (DGP) can be tested from measurements of the expansion history of the universe and the formation of structure. Current constraints on the expansion history from...
Knox, Lloyd, Song, Yong-Seon, Zhan, Hu
With a wariness of Occam's razor awakened by the discovery of cosmic acceleration, we abandon the usual assumption of zero mean curvature and ask how well it can be determined by planned surveys. We...
A Cosmological Test of Standard Gravity by Weak Lensing (2006)
The large scale structure formation in the standard Einstein gravity at later time is uniquely determined by the expansion history H(z) measured by the geometrical factor. A possible departure from...
Constraints on supernovae dimming from photon-pseudo scalar coupling (2005)
An alternative mechanism that dims high redshift supernovae without cosmic acceleration utilizes an oscillation of photons into a pseudo-scalar particle during transit. Since angular diameter...
Looking for an extra dimension with tomographic cosmic shear (2004)
The cosmic acceleration was discovered in one of the brane-based models. We are interested in discriminating this model from the dark energy by tomographic cosmic shear. Growth factors are different...
The application of weak lensing / (2004)
Thesis (Ph. D.)--University of California, Davis, 2004.
We study how parameter error forecasts for tomographic cosmic shear observations are affected by sky coverage, density of source galaxies, inclusion of CMB experiments, simultaneou fitting of...
The Detectability of Departures from the Inflationary Consistency Equation (2003)
We study the detectability, given CMB polarization maps, of departures from the inflationary consistency equation, r \equiv T/S \simeq -5 n_T, where T and S are the tensor and scalar contributions to...
Determining Neutrino Mass from the CMB Alone (2003)
Kaplinghat, Manoj, Knox, Lloyd, Song, Yong-Seon
Distortions of Cosmic Microwave Background (CMB) temperature and polarization maps caused by gravitational lensing, observable with high angular resolution and high sensitivity, can be used to...
Holographic Limitations of the Effective Field Theory of Inflation (2002)
Albrecht, Andreas, Kaloper, Nemanja, Song, Yong-Seon
Holographic considerations may provide a glimpse of quantum gravity beyond what is currently accessible by other means. Here we apply holography to inflationary cosmology. We argue that the...
The Far-Infrared Background Correlation with CMB Lensing (2002)
Song, Yong-Seon, Cooray, Asantha, Knox, Lloyd, Zaldarriaga, Matias
The intervening large--scale structure distorts cosmic microwave background (CMB) anisotropies via gravitational lensing. The same large--scale structure, traced by dusty star--forming galaxies, also...
A limit on the detectability of the energy scale of inflation (2002)
We show that the polarization of the cosmic microwave background can be used to detect gravity waves from inflation if the energy scale of inflation is above 3.2 times 10^15 GeV. These gravity waves...