Dr Ricardo Monteiro

Research

Gravity, Quantum field theory, String theory

Interests

I have a broad interest in high-energy theoretical physics. My recent work focuses on perturbative aspects of quantum field theory, quantum gravity and string theory.

One of my main areas of activity has been the perturbative description of gravity as a double copy of gauge theory. This idea appeared in the study of scattering amplitudes, which are notoriously complicated in theories of gravity if traditional methods are used. The double-copy technique allows us to perform certain gravity computations using much simpler computations in gauge theory. My goals here are two-fold: to investigate the mathematical structure behind the double copy, including at loop level (quantum effects), and to apply this technique to a wider set of problems, including the study of classical solutions (perturbative or exact) in gravity theories. A highlight of my work has been the interpretation of exact black hole solutions as a double copy of gauge theory solutions.

My other major line of work is the description of certain quantum field theories in terms of worldsheet models inspired by string theory, known as ambitwistor strings. These models underlie a new mathematical formalism for the scattering amplitudes of massless particles, based on scattering equations that relate the kinematic invariants to the moduli space of a sphere. My main focus here has been the extension of this very interesting formalism to loop level, which opens the possibility of a much wider application. Both gauge theory and gravity admit this type of formalism, and this is also a promising avenue to understand the double-copy relation at a more fundamental level. In addition, my recent work has shown how this progress for field theory amplitudes can be imported into fully-fledged string theory, where the amplitudes are much more involved.

Apart from these topics, I maintain my interest for areas in which I have worked in the past. These include black holes in general relativity and in string theory, and the AdS/CFT correspondence between a theory of gravity (string theory) and a lower-dimensional (conformal) field theory.

Interest/expertise relevant to this research centre: my expertise falls entirely within the remit of the Centre for Fundamental Physics.

Publications

2024

2023

2022

2021

2020

2019

2018

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2015

2014

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2012

2011

2010

2009

2005

Grants