Research Field

Two pillars of modern theoretical physics are Quantum Mechanics and General Relativity. Each theory describes physics very well in the appropriate regime: General Relativity describes the physics of gravity over large scales, while Quantum Mechanics describes physics on small scales. But there is only one universe, and so there must exist a single theory which is valid on all length scales. A theory which consistently combines quantum mechanics with general relativity is a theory of Quantum Gravity.

My work focuses on what properties a theory of Quantum Gravity must have. One of the main tools I utilise is String Theory which is our only well-understood theory of quantum gravity. I study what String Theory can teach us about what type of theories of physics can be consistent with quantum gravity (theories which are not-consistent are said to belong to the Swampland), and what are the resulting implications for a wide range of physical questions, from fundamental particle physics to cosmology.  

All my academic publications can be found here:   

Example Topics

These are research projects based on my papers. For student projects see my Group page.

Quantum Gravity and the Swampland

Physical theories which include gravity must complete at high energies to theories of quantum gravity. But which types of theories can be completed this way? Theories of physics which appear completely consistent at low energies but nonetheless have no consistent ultraviolet (high-energy) completion are termed to lie in the Swampland. The Swampland program aims to determine what are the conditions on a theory of physics in order to allow for a consistent ultraviolet completion to quantum gravity.  Read more...

Large Field Inflation and Primordial Gravitational Waves

One of the most sought-after signals in contemporary cosmology are signs of primordial gravitational waves that could have been produced in the early universe during inflation. Theories which produce such gravitational waves require inflation to occur at very high energy scales and also that the inflaton field obtain an expectation value larger than the Planck mass. Understanding the physics of such large expectation values requires understanding how quantum gravity behaves in such circumstances. I use string theory to learn about such physics and research whether it is actually possible or fundamentally obstructed.  Read more...

Particle Physics models and F-theory

The standard model of particle physics consists of a gauge symmetry group SU(3)xSU(2)xU(1) and matter which carries certain charges under it. One of the topics which interests me is how to realise such a spectrum of gauge groups and charged particles in String Theory. A particularly attractive paradigm is that of Grand Unification which proposes that the three gauge groups of the Standard Model actually unify into a single group SU(5) at high energies. Realising such unification in String theory requires going to a strongly coupled regime called F-theory. The strong coupling presents a challenge to understanding how to construct the particle physics models, but using sophisticated mathematical tools in algebraic geometry it is possible to reformulate the particle physics geometrically in terms of properties of elliptic fibrations in higher dimensions. I work on this dictionary between particle physics and geometry in F-theory. Read more...