Publications associées à QCD worldsheet axion from the bootstrap

Seeking the new, learning from the unexpected: Computational models of surprise and novelty in the brain

Human babies have a natural desire to interact with new toys and objects, through which they learn how the world around them works, e.g., that glass shatters when dropped, but a rubber ball does not. When their predictions are proven incorrect, such as whe ...

EPFL2024

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

Thermo-hydro-mechanical behavior of energy barrettes: Field experiments and numerical simulations

Lyesse Laloui, Alessandro Francesco Rotta Loria, Elena Ravera

Over the past two decades, the thermo-hydro-mechanical behavior of earth-contact structures such as piles, walls, slabs, and tunnels, which simultaneously provide structural support and energy supply, has been studied through various field experiments and ...

ELSEVIER2023

Behavioral outcome of very preterm children at 5 years of age: Prognostic utility of brain tissue volumes at term-equivalent-age, perinatal, and environmental factors

Djalel Eddine Meskaldji, Laura Ioana Gui, Serafeim Loukas

ObjectivePrematurity is associated with a high risk of long-term behavioral problems. This study aimed to assess the prognostic utility of volumetric brain data at term-equivalent-age (TEA), clinical perinatal factors, and parental social economic risk in ...

WILEY2023

Social isolation shortens lifespan through oxidative stress in ants

Alessandro Crespi, Laurent Keller

Social isolation negatively affects health, induces detrimental behaviors, and shortens lifespan in social species. Little is known about the mechanisms underpinning these effects because model species are typically short-lived and non-social. Using coloni ...

Nature Research2023

Where is M-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, 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

Engineering of Existing Structures: The Need and Place for Non-destructive Evaluation

Eugen Brühwiler, Numa Joy Bertola, Thomas Schumacher

Structural engineers today are still educated mainly to design new structures. This ignores the fact that structures already exist and need to be maintained. Students are thus often ill-equipped to deal with maintenance and preservation of existing structu ...

2022

Role of Stress History on the Swelling-Shrinkage Behavior of Compacted Scaly Clay

Alessio Ferrari

Compacted scaly clays are complex geomaterials widely used for the realization of dam cores and waste dump liners. This research aims to investigate the swelling/shrinkage behavior of these geomaterials subjected in an oedometric cell to complex hydromecha ...

ASCE-AMER SOC CIVIL ENGINEERS2022

Morphological Sensitivity and Falling Behavior of Paper V-Shapes

Josephine Anna Eleanor Hughes

Behavioral diversity seen in biological systems is, at the most basic level, driven by interactions between physical materials and their environment. In this context we are interested in falling paper systems, specifically the V-shaped falling paper (VSFP) ...

MIT PRESS2022

Stochastic gravitational-wave background from metastable cosmic strings

Valerie Fiona Domcke

A metastable cosmic-string network is a generic consequence of many grand unified theories (GUTs) when combined with cosmic inflation. Metastable cosmic strings are not topologically stable, but decay on cosmic time scales due to pair production of GUT mon ...

IOP Publishing Ltd2021

The S-matrix Bootstrap Reloaded

Aditya Hebbar

Quantum field theories (QFTs) are the backbone upon which the edifice of modern physics is built. In this thesis we explore the S-matrix bootstrap which is a non-perturbative method that constrains the vast space of QFTs by using consistency conditions tha ...

EPFL2021

An analytical toolkit for the S-matrix bootstrap

Miguel Alexandre Ribeiro Correia, Amit Sever, Alexander Zhiboedov

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 ...

Springer Nature2021

Strong temperature-dependent thermoelectric power of IrMn(3)thin films of different thicknesses

Jean-Philippe Ansermet, Haiming Yu, Junfeng Hu, Mukund Krishna Kothari

IrMn(3)thin films were experimentally characterized by thermoelectric power and resistivity as a function of temperature and sample thickness. The Seebeck coefficient shows strong temperature dependence and the value increases with temperature up to 350 K. ...

IOP PUBLISHING LTD2021

Orchestration of oscillatory activity to improve visual motion discrimination

Roberto Felipe Salamanca Giron

This thesis describes advances in the use of novel configurations of non-invasive brain stimulation over the visual system allowing to modulate of modifying electro-physiological activity, interregional interactions and by it, visual behavior such as motio ...

EPFL2021

Learning Optimal Impedance Control During Complex 3D Arm Movements

Sylvain Calinon

In daily life, humans use their limbs to perform various movements to interact with an external environment. Thanks to limb's variable and adaptive stiffness, humans can adapt their movements to unstable dynamics of the external environments. The underlyin ...

IEEE2021

Fractal-like Mechanical Resonators with a Soft-Clamped Fundamental Mode

Tobias Kippenberg, Sergey Fedorov, Nils Johan Engelsen, Alberto Beccari

Self-similar structures occur naturally and have been employed to engineer exotic physical properties. We show that acoustic modes of a fractal-like system of tensioned strings can display increased mechanical quality factors due to the enhancement of diss ...

AMER PHYSICAL SOC2020

Solidity without inhomogeneity: perfectly homogeneous, weakly coupled, UV-complete solids

Angelo Esposito

Solid-like behavior at low energies and long distances is usually associated with the spontaneous breaking of spatial translations at microscopic scales, as in the case of a lattice of atoms. We exhibit three quantum field theories that are renormalizable, ...

Springer Nature2020

Personalizable intervention systems to promote healthy behavior change

Igor Kulev

Adopting healthy behaviors can prevent the onset of many adverse health conditions. However, behavior changes are difficult to make, and often, people who like to improve their behaviors do not know how to do that. Personalizable intervention systems could ...

EPFL2020

Tapping into Multi-Faceted Human Behavior and Psychopathology Using fMRI Brain Dynamics

Dimitri Nestor Alice Van De Ville, Thomas William Arthur Bolton, Maria Giulia Preti, Elenor Morgenroth

Human behavior comprises many aspects that stand out by their dynamic nature. To quantify its neural underpinnings, time-resolved fMRI methods have blossomed over the past decade. In this review we conceptually organize a broad repertoire of dynamic analyt ...

2020

Filamentous and step-like behavior of gelling coarse fibrin networks revealed by high-frequency microrheology

László Forró, Sylvia Jeney

By a micro-experimental methodology, we study the ongoing molecular process inside coarse fibrin networks by means of microrheology. We made these networks gelate around a probe microbead, allowing us to observe a temporal evolution compatible with the wel ...

ROYAL SOC CHEMISTRY2020