Pengjie Zhang

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Modifications of general relativity provide an alternative explanation to dark energy for the observed acceleration of the Universe. Modified gravity theories have richer observational consequences for large scale structures than conventional dark energy models, in that different observables are not described by a single growth factor even in the linear(More)
We develop a new tool to generate statistically precise dark matter maps from the cosmic magnification of galaxies with distance estimates. We show how to overcome the intrinsic clustering problem using the slope of the luminosity function, because magnification changes strongly over the luminosity function, while intrinsic clustering only changes weakly.(More)
We use one-dimensional numerical simulations to study spherical collapse in the ƒ(R) gravity models. We include the nonlinear self-coupling of the scalar field in the theory and use a relaxation scheme to follow the collapse. We find an unusual enhancement in density near the virial radius which may provide observable tests of gravity. We also use the(More)
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