Dr Sunny Vagnozzi

My research interests lie broadly at the intersection of cosmology, astrophysics, and particle physics. I work at the interface of  data analysis, theory, phenomenology, and experiments. My goal, through precision cosmological and astrophysical data, is: to identify those models which best describe our Universe, and in particular its dark components - dark matter (DM) and dark energy (DE); to constrain the parameters of these models and define goals for future experiments; and likewise to construct viable data-driven theoretical models. This back-and-forth interplay between existing data, future experiments, and theory, represents my main research strength.

Data-wise my primary focus is on Cosmic Microwave Background (CMB) and large-scale structure (LSS) data. I am interested in how combinations and/or cross-correlations between CMB and LSS can fully bring into play the synergy between these two probes. I am a member of the Simons Observatory collaboration, which will provide exquisitely accurate maps of the CMB sky from the Atacama Desert. I have recently begun exploring new windows onto fundamental physics, including future gravitational wave experiments and images of black hole shadows.

A significant part of my data-driven interests has been neutrino cosmology, particularly how to extract information on neutrino masses and their mass ordering in a robust way, and reduce systematics (for instance related to galaxy bias) which might limit our understanding of neutrino properties. Other aspects of fundamental physics I have worked towards probing include inflationary models, DE models, interactions between DE and DM, unified dark sector models, extra dimensions, axions, modifications to General Relativity (GR), and possible observable manifestations of string theory such as the string axiverse, AdS vacua, and astrophysical violations of the Kerr bound.

Theory-wise my focus is on models of DM, DE, and cosmic inflation. My main interests in these directions have been related to constructing alternative models for the dark components of our Universe which address some of the most important shortcomings of the standard ΛCDM paradigm on both cosmological and astrophysical scales. Examples include models with strong DM self-interactions, interactions between DM and DE, or modifications to GR. At the same time, I have worked on predicting signatures of such models in cosmological as well as astrophysical observations, and DM experiments.

I joined the University of Cambridge in October 2019 as a Newton-Kavli Fellow within the Kavli Institute for Cosmology (KICC) and the Institute of Astronomy (IoA), jointly funded by the Kavli Foundation and the Isaac Newton Trust. I am also affiliated to the Department of Applied Mathematics and Theoretical Physics (DAMTP) and am a research associate at Homerton College. Earlier in 2019 I earned my PhD in Theoretical Physics at Stockholm University (you can read my thesis here), where my primary advisor was Prof. Katherine Freese.