Massimo Meneghetti

Research

My main research interests are in cosmology and structure formation. Since I was a Ph.D. students I used gravitational lensing to investigate the internal structure of the cosmic structure. By doing this, we can learn how dark matter is districuted and how dark energy affects the growth of the cosmic structures.

I developed a particular interest towards galaxy clusters, the largest gravitationally bound structures in the Universe. Because of their large mass (up to several millions of billions of solar masses), these are the strongest gravitational lenses in the sky. Their gravitational field induces large distortions on the images of distant sources and sometimes allow to see them in the form of multiple images. In rather rare cases, gravitationally lensed galaxies appear as giant gravitational arcs near the cluster centers, where the lens surface density reaches the highest values.

Multiple images and arcs trace the lensing potential in the cluster cores. Weaker lensing effects can be detected also at larger distances via the measurement of spatially coherent ellipticities of galaxies in the cluster background. The combination of these weak lensing measurements and of the stronger effects detectable near the cluster center allow to trace the distribution of dark and baryonic matter over a broad range of distances, from few tens of kpc to few Mpc.

The lensing induced distortions change the solid angle under which sources are observed without changing their surface brightness. Consequently, gravitational lensing causes magnifications and de-magnifications. Due to their huge lensing power, galaxy clusters can act as cosmic telescopes, enabling the observation of sources which could not be detected otherwise, even with the most powerful instruments available to date.

To learn about some of the projects in which I am involved, click the buttons below.

• The Euclid mission
• CLASH
• Frontier Fields