I will discuss parity violation in the early universe. I’ll outline a no-go theorem that states that vanilla inflation cannot produce parity-violating inflationary correlators, then show how including additional massive states in the early universe can yield non-zero signals that take an intriguing factorised form. For example, the parity odd four-point function of scalar perturbations can be...
Recent cosmological observations suggest that dark energy, the driver of the universe's accelerated expansion, may be evolving over time. This challenges the conventional idea of a static cosmological constant within the standard model of cosmology. In this talk, I will explore recent theoretical developments in understanding the nature of dark energy from the perspective of string theory....
Open effective field theories seek to incorporate dissipation and noise into our theoretical toolbox. These effects arise from the incomplete modelling of unknown components, which can significantly alter the dynamics of observable degrees of freedom. In this talk, I will introduce open electromagnetism, a sandbox for exploring gauge symmetries in open systems, which describes light in...
The basic observables in cosmology are known as in-in correlators. Recent calculations have revealed that in-in correlators in de Sitter space exhibit hidden simplicity stemming from a close relation to scattering amplitudes in flat space. In this talk, I will explain how to make this property manifest by dressing flat space Feynman diagrams with certain auxiliary propagators. Such dressing...
In this talk, I will explore how the self-dual sector of gravity and Yang-Mills theory provides a natural framework for formulating an elegant version of the double copy in curved spacetimes. Additionally, I will discuss how this perspective sheds light on the soft limits of these theories, offering a deeper understanding of their asymptotic behaviour.
