Research Highlights

Research Highlights

  • The notion of self acceleration has been introduced as a convenient way to theoretically distinguish cosmological models in which acceleration is due to modified gravity from those in which it is due to the properties of matter or fields. In this paper we review the concept of self acceleration as given, for example, by [1],

  • DeepMass: The first Deep Learning reconstruction of dark matter maps from weak lensing observational data (DES SV weak lensing data)DeepMass This is the first reconstruction of dark matter maps from weak lensing observational data using deep learning. We train a convolution neural network (CNN) with a Unet based architecture on over 3.6 x 10^5 simulated data

  • Diffuse Galactic thermal dust emission: modified black-body parameter maps Diffuse emissions are ubiquitous within our Galaxy. They probe star-forming regions, the chemical composition of the Galaxy and the Galactic magnetic field. Conversely, they also obscure cosmological measurements such as the cosmic microwave background and the epoch of reionisation signal. Detailed characterisation of these emissions is

  • Weak lensing 2D & 3D density fluctuation map reconstruction The 3D tomographic weak lensing is one of the most important tools for modern cosmology:  Underlying the link between weak lensing and the compressed sensing theory, we have proposed a  new approach to reconstruct the dark matter distribution in two and three dimensions, using photometric redshift

  • Cosmology and Fundamental Physics with the Euclid Satellite Understanding the source of cosmic acceleration in the universe is one of the major challenges that will be addressed by future surveys like the Euclid space mission. Acceleration may be caused by a cosmological constant or by a dynamical fluid (dark energy) or rather be a sign

  • Radio-Interferometry: Improving the Resolution by a Factor of 4 (2 in each spatial dimension) Sparse recovery allows us to reconstruct radio-interferometric images with a resolution increased by a factor two. This has been confirmed by comparing two images of the Cygnus A radio source, the first one from the LOFAR instrument and reconstructed using sparsity,

  • Cosmic Microwave Background: Joint WMAP/Planck CMB Map Recovery The LGMCA method has been used to reconstruct the Cosmic Microwave Background (CMB) image from WMAP 9 year and Planck-PR2 data. Based on the sparse modeling of signals , the LCS component separation method is well-suited for the extraction of foreground emissions. A joint WMAP9 year and

  • Cosmic Microwave Background: Large Scale Non Gaussianities Studies If the LGMCA map (Bobin et al, A&A, 2014) presented above is used, then LCS has shown that this map is clean enough so no masking  is required anymore for large scale statistical analysis. We have found the most claimed anomalies in the CMB map disappear if

  • CFHTLenS: Constraining the Dark Universe with weak lensing from the CFHT Lensing Survey We have taken part in the largest galaxy survey to measure the distribution of dark matter in the Universe using the gravitational lensing effect. More than 4.2 million galaxies have been observed for over 500 nights at the Canada-France Hawaii Telescope (CFHT)