Concept

Amplitude de diffusion

Publications associées (49)

Nonperturbative aspects of scattering amplitudes

In this thesis we study how physical principles imposed on the S-matrix, such as Lorentz invariance, unitarity, crossing symmetry and analyticity constrain quantum field theories at the nonperturbative level. We start with a pedagogical introduction to the ...

EPFL2023

Spatial symmetries in nonlocal multipolar metasurfaces

Olivier Martin, Karim Achouri, Ville Tuovi Tiukuvaara

We propose a framework that connects the spatial symmetries of a metasurface to its material parameter tensors and its scattering matrix. This provides a simple and universal way to effortlessly determine the properties of a metasurface scattering response ...

SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS2023

Where is M-theory in the space of scattering amplitudes?

Andrea Guerrieri

We use the S-matrix bootstrap to carve out the space of unitary, analytic, crossing symmetric and supersymmetric graviton scattering amplitudes in nine, ten and eleven dimensions. We extend and improve the numerical methods of our previous work in ten dime ...

SPRINGER2023

Bounds on photon scattering

Denis Karateev, Kelian Philippe Häring, Marco Meineri, Aditya Hebbar

We study 2-to-2 scattering amplitudes of massless spin one particles in

d=4

space-time dimensions, like real world photons. We define a set of non-perturbative observables (Wilson coefficients) which describe these amplitudes at low energies. We use full ...

2022

Spin-dependent gravitational tail memory in D=4

Biswajit Sahoo

We derive the leading spin-dependent gravitational tail memory, which appears at the second post-Minkowskian order and behaves as u(-2) for large retarded time u. This result follows from the classical soft graviton theorem at order omega In omega as a low ...

AMER PHYSICAL SOC2022

An analytical toolkit for the S-matrix bootstrap

Alexander Zhiboedov, Miguel Alexandre Ribeiro Correia, Amit Sever

We revisit analytical methods for constraining the nonperturbative S-matrix of unitary, relativistic, gapped theories in d >= 3 spacetime dimensions. We assume extended analyticity of the two-to-two scattering amplitude and use it together with elastic uni ...

SPRINGER2021

Positive moments for scattering amplitudes

Riccardo Rattazzi, Francesco Riva, Brando Bellazzini, Marc Riembau Saperas

We find the complete set of conditions satisfied by the forward 2 -> 2 scattering amplitude in unitary and causal theories. These are based on an infinite set of energy dependent quantities (the arcs) which are dispersively expressed as moments of a positi ...

AMER PHYSICAL SOC2021

Where Is String Theory in the Space of Scattering Amplitudes?

Andrea Guerrieri

We use the S-matrix bootstrap to carve out the space of unitary, crossing symmetric and supersymmetric graviton scattering amplitudes in ten dimensions. We focus on the leading Wilson coefficient a controlling the leading correction to maximal supergravity ...

AMER PHYSICAL SOC2021

A scattering amplitude in Conformal Field Theory

Marco Meineri, Marc Gillioz

We define form factors and scattering amplitudes in Conformal Field Theory as the coefficient of the singularity of the Fourier transform of time-ordered correlation functions, as p(2) -> 0. In particular, we study a form factor F(s, t, u) obtained from a ...

SPRINGER2020

Semiclassical S-matrix and black hole entropy in dilaton gravity

Sergey Sibiryakov

We use complex semiclassical method to compute scattering amplitudes of a point particle in dilaton gravity with a boundary. This model has nonzero minimal black hole mass M-cr. We find that at energies below M-cr the particle trivially scatters off the bo ...

SPRINGER2020

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