Concept

Histoire de la théorie des cordes

Publications associées (18)

Bootstrapping amplitudes of scalar particles

Quantum Field Theories are a central object of interest of modern physics, describing fundamental interactions of matter. However, current methods give limited insight into strongly coupling theories. S-matrix bootstrap program, described in this thesis, a ...

EPFL2024

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

Andrea Guerrieri, João Miguel Augusto Penedones Fernandes

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 ...

Springer Nature2023

Nonperturbative aspects of scattering amplitudes

Miguel Alexandre Ribeiro Correia

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

Where Is String Theory in the Space of Scattering Amplitudes?

João Miguel Augusto Penedones Fernandes, 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

Non-Wilson-Fisher kinks of O(N) numerical bootstrap: From the deconfined phase transition to a putative new family of CFTs

Ning Su

It is well established that the O(N) Wilson-Fisher (WF) CFT sits at a kink of the numerical bounds from bootstrapping four point function of O(N) vector. Moving away from the WF kinks, there indeed exists another family of kinks (dubbed non-WF kinks) on th ...

2021

Bootstrapping massive quantum field theories

Denis Karateev, João Miguel Augusto Penedones Fernandes

We propose a new non-perturbative method for studying UV complete unitary quantum field theories (QFTs) with a mass gap in general number of spacetime dimensions. The method relies on unitarity formulated as positive semi-definiteness of the matrix of inne ...

Springer Nature2020

Normalized Gaussian path integrals

Giulio Corazza

Path integrals play a crucial role in describing the dynamics of physical systems subject to classical or quantum noise. In fact, when correctly normalized, they express the probability of transition between two states of the system. In this work, we show ...

AMER PHYSICAL SOC2020

Experimental observation of the acoustic Z2 Weyl semimetallic phase in synthetic dimensions

Romain Christophe Rémy Fleury, Farzad Zangeneh Nejad

Scalar waves such as airborne sound lack an intrinsic spin degree of freedom, making the realization of sonic Z2 topological phases based on spin degeneracy challenging. Here, we demonstrate the relevance of synthetic dimensions and higher-dimensional topo ...

2020

Scalar-fermion analytic bootstrap in 4D

Denis Karateev

In this work we discuss an analytic bootstrap approach [1, 2] in the context of spinning 4D conformal blocks [3, 4]. As an example we study the simplest spinning case, the scalar-fermion correlator. We find that to every pair of primary scalar phi and ferm ...

Springer Nature2019

Graviton scattering and a sum rule for the c anomaly in 4D CFT

Marc Gillioz

4D CFTs have a scale anomaly characterized by the coefficient c, which appears as the coefficient of logarithmic terms in momentum space correlation functions of the energy-momentum tensor. By studying the CFT contribution to 4-point graviton scattering am ...

Springer Nature2018

Constraints on perturbative RG flows in six dimensions

Lorenzo Vitale

When conformal field theories (CFTs) are perturbed by marginally relevant deformations, renormalization group (RG) flows ensue that can be studied with perturbative methods, at least as long as they remain close to the original CFT. In this work we study s ...

Springer Nature2016

Supersymmetric vacua in N=2 supergravity

Paul Smyth

We use the embedding tensor formalism to analyse maximally symmetric backgrounds of N = 2 gauged supergravities which have the full N = 2 supersymmetry. We state the condition for N = 2 vacua and discuss some of their general properties. We show that if th ...

Springer Nature2012

A reduced basis model with parametric coupling for fluid-structure interaction problems

Alfio Quarteroni, Gianluigi Rozza, Toni Mikael Lassila

We present a new model reduction technique for steady fluid-structure interaction problems. When the fluid domain deformation is suitably parametrized, the coupling conditions between the fluid and structure can be formulated in the low-dimensional space o ...

Society for Industrial and Applied Mathematics2012

Supersymmetric sound in fluids

Boaz Keren Zur

We consider the hydrodynamics of supersymmetric fluids. Supersymmetry is broken spontaneously and the low energy spectrum includes a fermionic massless mode, the phonino. We use two complementary approaches to describe the system: First, we construct a gen ...

Springer Nature2012

No metastable de Sitter vacua in N=2 supergravity with only hypermultiplets

Claudio Scrucca

We study the stability of vacua with spontaneously broken supersymmetry in N = 2 supergravity theories with only hypermultiplets. Focusing on the projection of the scalar mass matrix along the sGoldstino directions, we are able to derive a universal upper ...

Springer Nature2009

Universal constraints on conformal operator dimensions

Alessandro Vichi

We continue the study of model-independent constraints on the unitary conformal field theories (CFTs) in four dimensions, initiated in [R. Rattazzi, V. S. Rychkov, E. Tonni, and A. Vichi, J. High Energy Phys. 12 (2008) 031]. Our main result is an improved ...

American Physical Society2009

The Coherence of Theories-Dependencies and Weights

Jingshi Li

One way to evaluate and compare rival but potentially incompatible theories that account for the same set of observations is coherence. In this paper we take the quantitative notion of theory coherence as proposed by [Kwok, et.al. 98] and broaden its found ...

Springer2009

Soft masses in superstring models with anomalous U(1) symmetries

Claudio Scrucca

We analyze the general structure of soft scalar masses emerging in superstring models involving anomalous U(1) symmetries, with the aim of characterizing more systematically the circumstances under which they can happen to be flavor universal. We consider ...

Springer Nature2007