Small fluctuations around homogeneous and isotropic expanding backgrounds are the main
object of study in cosmology. Their origin and evolution is sensitive to the physical …

Since the discovery of the accelerated expansion of the present universe, significant
theoretical developments have been made in the area of modified gravity. In the meantime …

Fundamental principles of local quantum field theory or of quantum gravity can enforce
consistency requirements on the space of consistent low-energy effective field theories. We …

A bstract The wavefunction in quantum field theory is an invaluable tool for tackling a variety
of problems, including probing the interior of Minkowski spacetime and modelling boundary …

S-matrix bootstrap and positivity bounds are usually viewed as constraints on low-energy
theories imposed by the requirement of a standard UV completion. By considering graviton …

Physical principles such as unitarity, causality, and locality can constrain the space of
consistent effective field theories (EFTs) by imposing two-sided bounds on the allowed …

A bstract We study two-to-two scattering amplitudes of a scalar particle of mass m. For
simplicity, we assume the presence of ℤ 2 symmetry and that the particle is ℤ 2 odd. We …

A bstract We derive new effective field theory (EFT) positivity bounds on the elastic 2→ 2
scattering amplitudes of massive spinning particles from the standard UV properties of …

A bstract We compute the causality/positivity bounds on the Wilson coefficients of scalar-
tensor effective field theories. Two-sided bounds are obtained by extracting IR information …

A bstract Resumming quantum fluctuations at the level of the gravitational path integral is
expected to result in non-local effective actions and thus in a non-trivial momentum …