Sunday. Did lots of German reading and translation about cleaning and banking over the weekend. Now I'm caught up with all the mails that came this way.
1201.5121
The Lyman alpha forest flux probability distribution at z>3
Calura et al
Present Lyman alpha flux PDF measured from a set of 8 high resolution quasar.
* "Population of discrete lines in Lya forest are due to HI absorption arising from the filamentary structure of the cosmic-web, and in the approximation of a Gaussian velocity dispersion can be well described by a series of Voigt profiles. A variable amount of absorption in the Lya forest is also due to UV transitions from heavy element ions which are usually associated with strong Lya lines."
1201.5127
The direction of gravity
Linder
Gravity can bend light and cause LSS to grow by pulling down; but it can accelerate the expansion of the Universe by pulling outward. Examine methods to test the properties of gravity through cosmological measurements. Consider specific possibilities for a sound gravitational theory based on Galileon shift symmetry. The evolution of the laws of gravity from the early universe to the present acceleration to the future fate carries rich information on this fundamental force of physics and on the mystery of dark energy.
1201.5214
Wavelet Helmholtz decomposition for WL mass map reconstruction
Deriaz, Starck, Pires
Derive convergence field from gravitational shear of BG galaxy images: classical method require a convolution of the shear to be performed over the entire sky, usually expressed thanks to the FFT. However, it is not optimal for an imperfect geometry survey. Furthermore, FFT implicitly uses periodic conditions that introduce errors to the reconstruction. Method proposed that relies on computation of an intermediate field u that combines the derivatives of gamma and on convolution with a Green kernel. Study the wavelet Helmholtz decomposition as a new approach to reconstructing the DM mass map. Show that a link exists between the Helmholtz decomposition and the E/B mode separation. Introduce a new wavelet construction, that has a property that gives more flexibility in handling the border problem, and propose a nwe methods of reconstruction the DM mass map in the wavelet space. Set of experiments based on noise-free images illustrates that the Wavelet Helmholtz decomposition reconstructs the borders better than all other existing methods.
* "Population of discrete lines in Lya forest are due to HI absorption arising from the filamentary structure of the cosmic-web, and in the approximation of a Gaussian velocity dispersion can be well described by a series of Voigt profiles. A variable amount of absorption in the Lya forest is also due to UV transitions from heavy element ions which are usually associated with strong Lya lines."
1201.5127
The direction of gravity
Linder
Gravity can bend light and cause LSS to grow by pulling down; but it can accelerate the expansion of the Universe by pulling outward. Examine methods to test the properties of gravity through cosmological measurements. Consider specific possibilities for a sound gravitational theory based on Galileon shift symmetry. The evolution of the laws of gravity from the early universe to the present acceleration to the future fate carries rich information on this fundamental force of physics and on the mystery of dark energy.
1201.5214
Wavelet Helmholtz decomposition for WL mass map reconstruction
Deriaz, Starck, Pires
Derive convergence field from gravitational shear of BG galaxy images: classical method require a convolution of the shear to be performed over the entire sky, usually expressed thanks to the FFT. However, it is not optimal for an imperfect geometry survey. Furthermore, FFT implicitly uses periodic conditions that introduce errors to the reconstruction. Method proposed that relies on computation of an intermediate field u that combines the derivatives of gamma and on convolution with a Green kernel. Study the wavelet Helmholtz decomposition as a new approach to reconstructing the DM mass map. Show that a link exists between the Helmholtz decomposition and the E/B mode separation. Introduce a new wavelet construction, that has a property that gives more flexibility in handling the border problem, and propose a nwe methods of reconstruction the DM mass map in the wavelet space. Set of experiments based on noise-free images illustrates that the Wavelet Helmholtz decomposition reconstructs the borders better than all other existing methods.
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