423 citations · 5.5k across the 77 of their papers we have counts for
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Unitary and Analytic Renormalisation of Cosmological Correlators
Diksha Jain, Enrico Pajer, Xi Tong
Loop contributions to cosmological correlators and to the associated wavefunction are of key theoretical and phenomenological interest. Here, we investigate and compare different r…
On the Asymptotic Nature of Cosmological Effective Theories
Carlos Duaso Pueyo, Harry Goodhew, Ciaran McCulloch +1
Much of our intuition about Effective Field Theories (EFTs) stems from their formulation in flat spacetime, yet EFTs have become indispensable tools in cosmology, where time-depend…
An Open Effective Field Theory for light in a medium
Santiago Agui Salcedo, Thomas Colas, Enrico Pajer
In many scenarios of interest, a quantum system interacts with an unknown environment, necessitating the use of open quantum system methods to capture dissipative effects and envir…
Records from the S-Matrix Marathon: A Timeless History of Time
Mang Hei Gordon Lee, Enrico Pajer, Mathieu Giroux +3
By directly probing the initial conditions of our universe, cosmological surveys offer us a unique observational handle on quantum field theory in curved spacetime with dynamical g…
Perturbative unitarity bounds from momentum-space entanglement
Carlos Duaso Pueyo, Harry Goodhew, Ciaran McCulloch +1
Physical theories have a limited regime of validity and hence must be accompanied by a breakdown diagnostic to establish when they cease to be valid as parameters are varied. For p…
Cosmological cutting rules for Bogoliubov initial states
Diptimoy Ghosh, Enrico Pajer, Farman Ullah
The field theoretic wavefunction in cosmological spacetimes has received much attention as a fundamental object underlying the generation of primordial perturbations in our univers…
The Open Effective Field Theory of Inflation
Santiago Agui Salcedo, Thomas Colas, Enrico Pajer
In our quest to understand the generation of cosmological perturbations, we face two serious obstacles: we do not have direct information about the environment experienced by primo…
The In-Out Formalism for In-In Correlators
Yaniv Donath, Enrico Pajer
Cosmological correlators, the natural observables of the primordial universe, have been extensively studied in the past two decades using the in-in formalism pioneered by Schwinger…
A Cosmological Tachyon Collider: Enhancing the Long-Short Scale Coupling
Ciaran McCulloch, Enrico Pajer, Xi Tong
The squeezed limit of the primordial curvature bispectrum is an extremely sensitive probe of new physics and encodes information about additional fields active during inflation suc…
A Cosmological Bootstrap for Resonant Non-Gaussianity
Carlos Duaso Pueyo, Enrico Pajer
Recent progress has revealed a number of constraints that cosmological correlators and the closely related field-theoretic wavefunction must obey as a consequence of unitarity, loc…
Leading Loops in Cosmological Correlators
Mang Hei Gordon Lee, Ciaran McCulloch, Enrico Pajer
Cosmological correlators from inflation are often generated at tree level and hence loop contributions are bounded to be small corrections by perturbativity. Here we discuss a scen…
The Analytic Wavefunction
Santiago Agui Salcedo, Mang Hei Gordon Lee, Scott Melville +1
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 obse…
The graviton four-point function in de Sitter space
James Bonifacio, Harry Goodhew, Austin Joyce +2
We compute the tree-level late-time graviton four-point correlation function, and the related quartic wavefunction coefficient, for Einstein gravity in de Sitter spacetime. We deri…
Parity violation in the scalar trispectrum: no-go theorems and yes-go examples
Giovanni Cabass, Sadra Jazayeri, Enrico Pajer +1
We derive a set of no-go theorems and yes-go examples for the parity-odd primordial trispectrum of curvature perturbations. We work at tree-level in the decoupling limit of the Eff…
Snowmass White Paper: The Cosmological Bootstrap
Daniel Baumann, Daniel Green, Austin Joyce +4
This white paper summarizes recent progress in the cosmological bootstrap, an approach to the study of the statistics of primordial fluctuations from consistency with unitarity, lo…
A Differential Representation of Cosmological Wavefunctions
Aaron Hillman, Enrico Pajer
Our understanding of quantum field theory rests largely on explicit and controlled calculations in perturbation theory. Because of this, much recent effort has been devoted to impr…
Bootstrapping Large Graviton non-Gaussianities
Giovanni Cabass, Enrico Pajer, David Stefanyszyn +1
Gravitational interferometers and cosmological observations of the cosmic microwave background offer us the prospect to probe the laws of gravity in the primordial universe. To stu…
From Amplitudes to Contact Cosmological Correlators
James Bonifacio, Enrico Pajer, Dong-Gang Wang
Our understanding of quantum correlators in cosmological spacetimes, including those that we can observe in cosmological surveys, has improved qualitatively in the past few years.…
Cutting Cosmological Correlators
Harry Goodhew, Sadra Jazayeri, Mang Hei Gordon Lee +1
The initial conditions of our universe appear to us in the form of a classical probability distribution that we probe with cosmological observations. In the current leading paradig…
Cosmological Cutting Rules
Scott Melville, Enrico Pajer
Primordial perturbations in our universe are believed to have a quantum origin, and can be described by the wavefunction of the universe (or equivalently, cosmological correlators)…
From Locality and Unitarity to Cosmological Correlators
Sadra Jazayeri, Enrico Pajer, David Stefanyszyn
In the standard approach to deriving inflationary predictions, we evolve a vacuum state in time according to the rules of a given model. Since the only observables are the future v…
Building a Boostless Bootstrap for the Bispectrum
Enrico Pajer
The observation of primordial correlators by cosmological surveys is a very promising avenue to probe high energies and the perturbative regime of quantum gravity. Hence, it is imp…
The Cosmological Optical Theorem
Harry Goodhew, Sadra Jazayeri, Enrico Pajer
The unitarity of time evolution, or colloquially the conservation of probability, sits at the heart of our descriptions of fundamental interactions via quantum field theory. The im…
The Boostless Bootstrap: Amplitudes without Lorentz boosts
Enrico Pajer, David Stefanyszyn, Jakub Supeł
Poincaré invariance is a well-tested symmetry of nature and sits at the core of our description of relativistic particles and gravity. At the same time, in most systems Poincaré in…