We present a rigorous regularization of Rovellis's generalized projection operator in canonical 2+1 gravity. This work establishes a clear-cut connection between loop quantum gravity and the spin foam approach in this simplified setting. The point of view adopted here provides a new perspective to tackle the problem of dynamics in the physically

We study the time variation of fundamental constants in the early Universe. Using data from primordial light nuclei abundances, cosmic microwave background, and the 2dFGRS power spectrum, we put constraints on the time variation of the fine structure constant α and the Higgs vacuum expectation value ⟨v⟩ without assuming any theoretical framework. A

We present preliminary results of our HI WSRT observations of early-type galaxies in the ATLAS3D sample. We discuss the dependence of HI properties on environment. We detect HI in about half of the galaxies outside the Virgo cluster. The HI morphology/kinematics changes as a function of environment, going from regular, rotating systems around

We present preliminary results of a simultaneous X-ray/optical campaign of the proto-typical LMXB Sco X-1 at 1-10 Hz time resolution. Lightcurves of the high excitation Bowen/HeII emission lines were obtained through narrow interference filters with ULTRACAM, and these were cross-correlated with X-ray lightcurves. We find evidence for correlated

A dedicated mission to investigate exoplanetary atmospheres represents a major milestone in our quest to understand our place in the universe by placing our Solar System in context and by addressing the suitability of planets for the presence of life. EChO—the Exoplanet Characterisation Observatory—is a mission concept specifically geared for this

We present a photometric survey aimed at the identification of variable stars in the galactic globular cluster ω Cen. Our photometric catalogue is based on ~ 400 exposures of the central region of the cluster(Fov ~ 15' × 15') collected with the Danish Telescope. The catalogue has an accuracy of about ~ 0.02 mag at B ~ 18 mag. We present here