Carmelita Carbone (Institute of Space Astrophysics and Cosmic Physics IASF, Italy).
Title. “Science with Euclid”
Diego Blas (King’s College, UK).
Title. “Constraints on Ultra-Light Dark Matter from Galactic Rotation Curves”
Abstract. Bosonic ultra-light dark matter (ULDM) in the mass range m ~ 10-22 – 10-21 eV has been invoked as a motivated candidate with new input for the small-scale `puzzles’ of cold dark matter. Numerical simulations show that these models form cored density distributions at the center of galaxies (‘solitons’). These works also found an empirical scaling relation between the mass of the large-scale host halo and the mass of the central soliton. We show that this relation predicts that the peak circular velocity of the outskirts of the galaxy should approximately repeat itself in the central region. Contrasting this prediction to the measured rotation curves of well-resolved near-by galaxies, we show that ULDM in the mass range m ~ 10-22 – 10-21 eV is in tension with the data.
Ricardo Génova Santos (Instituto Astrofísico de Canarias, Spain).
Title. “Searching for the inflationary b-modes in the CMB polarization: experimental and observational challenges”.
Abstract. Over the last couple of decades, observations of the CMB temperature anisotropies, in combination with other cosmological probes, has allowed to measure cosmological parameters with sub-percent accuracy, leading to the so-called “concordance model”. An important ingredient of this model, which still lacks observational confirmation, is inflation, a period of violent accelerated expansion in the very early universe. Such confirmation could come from the B-mode signal, a specific pattern in the CMB polariastion imprinted by the background of gravitational waves (tensor modes) generated during the inflationary epoch of the Universe. The faintness of this signal, which is swamped by Galactic contaminants, instrument noise, and systematics, makes its detection an extremely challenging endeavour. Several experiments, operating at different frequency bands and using different technologies, have been desgined to try to detect this B-mode signal. In this talk I will give the general scientific context, I will go through the details of what are these observational challenges, and will describe some of these CMB polarization experiments, with special emphasis on the QUIJOTE experiment, which is performing observations in the 10-40 GHz band from the Teide Observatory (Spain), and whose data will become publicly available during this year.