Q+A with our new colleague, Dr Marco Fazzi

Dr Marco Fazzi joined the School of Mathematics and Statistics this January as a Lecturer. His research is at the interface of mathematical physics and algebraic geometry.

Portrait of Marco Fazzi

Can you tell us a bit about your career so far?

I completed my PhD in Physics in 2016 at the Université Libre de Bruxelles, with a dissertation titled ‘Higher-dimensional field theories from type II supergravity’. I then moved to the Technion in Israel as a postdoc for three years (2016-2019). I subsequently won a three-year (2019-2022) Marie Skłodowska-Curie Fellowship, co-held at the University of Milano-Bicocca and INFN Milano-Bicocca (where I was appointed fixed-term researcher). I later moved to Uppsala University (2022-2023) in Sweden for a final postdoc, before joining the University of Sheffield as lecturer. During my postdoc years I held several visiting positions (UCSB, US; Weizmann, Israel; SISSA, Italy; Nordita, Sweden). In 2018 I was awarded the Solvay Awards 2016 for an outstanding dissertation in the sciences, and a Jacob Shaham Fellowship Fund gift by the Aspen Center for Physics.

What sort of topics have you been working on as a researcher? Can you describe one of your main research topics?

I am a theoretical physicist interested in the mathematical modelling of high-energy processes. I specialize in string theory and quantum field theory. The latter are powerful theoretical frameworks which should be thought of as theories of theories (rather than comprising a single model). As a side hustle, I sometimes study (and use) mathematics, in particular algebraic and differential geometry, whose results and techniques feature prominently in string theory. A research topic I am passionate about is the string theory realization of holography known as AdS/CFT correspondence. Holography is an old concept of quantum gravity, positing that the gravitational degrees of freedom of a system can equivalently be described by a non-gravitational theory (such as a special quantum field theory) defined only on the boundary (rather than the interior) of the system. As a corollary to this, I have used AdS/CFT to define and count the so-called microstates (or quantum microscopic degrees of freedom) of special classes of black holes using powerful enumeration formulae valid in the ‘holographic dual’ quantum field theory. I also obtained results for rather exotic quantum field theories known as superconformal theories in dimensions 3, 4, and 6, culminating in the proof of (a version of the) ‘a-theorem’.

What made you want to join the School of Mathematics and Statistics at Sheffield?

The School hosts two strong internationally renowned groups (algebraic geometry and mathematical physics, gravitation and cosmology) with a high degree of overlap with my own research interests. One of my most recent endeavours was to utilize modern results in algebraic geometry to say something general about AdS/CFT and when it makes sense to speak about string theory on singular varieties. Another was to use AdS/CFT to enumerate the black hole microstates. This sort of cross-fertilization of ideas and topics, as well as the presence of strong research-focused groups, is what I looked for in a academic institution.

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