Bridging theory and observation in the quest for dark matter
Unveiling the nature of dark matter is one of today’s main challenges for particle physics and cosmology. A huge experimental effort has been deployed and new observational techniques developed in order to detect the first non-gravitational signature of dark matter. On the theory side, an accurate modelling of the expected dark matter signal is required as well as the understanding of the backgrounds that unavoidably affect any search. Dark matter indirect detection aims to discriminate the flux of stable particles (gamma rays and charged cosmic rays) coming from the annihilation or decay of dark matter from the dominant background induced by astrophysical processes. Therefore, the synergy between the study of the expected dark matter signal and the one of astrophysical foregrounds and backgrounds is a key element for indirect searches. In the bulk of my research activity, I have consistently tried to achieve this synergy and to learn more about both the dark matter in our Galaxy and the fundamental physics underlying the gamma-ray emission of high-energy sources. Besides, I am also very much interested in probing fundamental phenomena with multi-wavelength and multi-messenger observations. I am a phenomenologist, and I like the challenges coming together with the wealth of present data.
Main research topics of my activity
Characterising and interpreting the Fermi-LAT Galactic centre GeV excess.
I started to contribute to this topic back in 2015, when I carried out one of the most thorough analyses of the GeV excess at the time. Since 2016, I am scrutinizing possible multi-messenger (and multi-wavelength) probes of the GeV excess, in order to shed light onto its nature. I am leading a two-fold observational effort aimed at discovering pulsars and millisecond pulsars at radio and X-ray wavelengths respectively. More generally, I worked also on the Fermi-LAT sky at higher latitudes, trying to understand, on the one hand, the composition of the diffuse gamma-ray background as a superposition of multiple source classes and, on the other hand, the emission from other galaxies.
Scrutinising particle and non-particle dark matter candidates with astroparticle experiments.
Different, viable, dark matter candidates exist and can be probed with astroparticle experiments. More generally, I focused my research in constraining beyond-the-Standard-Model particles, which sometimes are also viable dark matter candidates, with high-energy astrophysics, covering weakly interacting massive particles, primordial black holes, axion-like and other feebly interacting particles.
I worked on numerical simulations for galaxy formation and the distribution of dark matter in haloes of different size (from dwarf galaxies to Milky-Way-like galaxies). I studied the consequences for indirect dark matter detection of different dark matter distributions, also studying dynamical effects such as the infall of the Large Magellanic Cloud onto the Milky-Way gravitational potential.
Exploring the gravitational waves connection.
As an exploratory activity, I got interested in the newly flourishing field of gravitational wave astronomy. In particular, I am motivated to export techniques traditionally adopted in gamma-ray data analysis and cosmology (such as the cross-correlation analysis) to gravitational wave data, in order to introduce new approaches to gravitational wave physics.
Francesca Calore 