Publications related to Canonical quantum gravity

Holography and localization of information in quantum gravity

Kyriakos Papadodimas, Alexandre Mathieu Frédéric Belin

Within the AdS/CFT correspondence, we identify a class of CFT operators which represent diff-invariant and approximately local observables in the gravitational dual. Provided that the bulk state breaks all asymptotic symmetries, we show that these operator ...

Springer Nature2024

A Cavity-Microscope for Quantum Simulations with Locally-Controllable All-to-All Interactions

Nick Jacob Sauerwein

This thesis presents the development, construction, and benchmark of an experimental platform that combines cold fermionic 6Li atoms with locally controllable light-matter interactions. To enable local control, a new device, the cavity-microscope, was crea ...

EPFL2024

A squeezed mechanical oscillator with millisecond quantum decoherence

Tobias Kippenberg, Amir Youssefi, Mahdi Chegnizadeh, Shingo Kono

An enduring challenge in constructing mechanical-oscillator-based hybrid quantum systems is to ensure engineered coupling to an auxiliary degree of freedom and maintain good mechanical isolation from the environment, that is, low quantum decoherence, consi ...

NATURE PORTFOLIO2023

Biomechanics at the workplace under hypogravity conditions

Tatiana Maillard

The main goal of my research is to establish guidelines for workplace design based on human biomechanics: specifically sitting workplaces and handling areas in 1/6G-1/3G (Moon, Mars) conditions. Such a workplace could be used in long-term space missions in ...

EPFL2022

Gravitational causality and the self-stress of photons

Brando Bellazzini, Giulia Isabella

We study causality in gravitational systems beyond the classical limit. Using on-shell methods, we consider the 1-loop corrections from charged particles to the photon energy-momentum tensor - the self-stress - that controls the quantum interaction between ...

Springer Nature2022

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

EEG microstates are a candidate endophenotype for schizophrenia

Michael Herzog, Ophélie Gladys Favrod, Christine Mohr, Janir Nuno Ramos Antunes Da Cruz, Maya Roinishvili, Patricia Figueiredo

Electroencephalogram microstates are recurrent scalp potential configurations that remain stable for around 90 ms. The dynamics of two of the four canonical classes of microstates, commonly labeled as C and D, have been suggested as a potential endophenoty ...

Nature Research2020

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 ...

Springer Nature2020

Frame (in)equivalence in quantum field theory and cosmology

Mario Herrero Valea

We revisit the question of frame equivalence in Quantum Field Theory in the presence of gravity, a situation of relevance for theories aiming to describe the early Universe dynamics and Inflation in particular. We show that in those cases, the path integra ...

Springer2019

Hidden and explicit quantum scale invariance

Sander Johannes Nicolaas Mooij, Mikhail Chapochnikov, Thibault Voumard

There exist renormalization schemes that explicitly preserve the scale invariance of a theory at the quantum level. Imposing a scale-invariant renormalization breaks renormalizability and induces new nontrivial operators in the theory. In this work, we stu ...

American Physical Society2019

Inflationary perturbations with Lifshitz scaling

Sergey Sibiryakov

Instead of Lorentz invariance, gravitational degrees of freedom may obey Lifshitz scaling at high energies, as it happens in Horava's proposal for quantum gravity. We study consequences of this proposal for the spectra of primordial perturbations generated ...

IOP PUBLISHING LTD2019

Rebounds of deformed cavitation bubbles

Mohamed Farhat, Danail Obreschkow, Outi Supponen

Presented here are experiments clarifying how the deformation of cavitation bubbles affects their rebound. Rebound bubbles carry the remaining energy of a bubble following its initial collapse, which dissipates energy mainly through shock waves, jets, and ...

AMER PHYSICAL SOC2018

Horava Gravity is Asymptotically Free in 2+1 Dimensions

Sergey Sibiryakov, Diego Blas Temino, Mario Herrero Valea

We compute the beta functions of marginal couplings in projectable Horava gravity in 2 + 1 spacetime dimensions. We show that the renormalization group flow has an asymptotically free fixed point in the ultraviolet (UV), establishing the theory as a UV-com ...

American Physical Society2017

Fermi resonance in CO2: Mode assignment and quantum nuclear effects from first principles molecular dynamics

Sara Bonella, Guillaume André Jean Fraux

Vibrational spectroscopy is a fundamental tool to investigate local atomic arrangements and the effect of the environment, provided that the spectral features can be correctly assigned. This can be challenging in experiments and simulations when double pea ...

Amer Inst Physics2017

Perturbative and non-perturbative aspects of RG flows in quantum field theory

Lorenzo Vitale

This thesis explores two aspects of the renormalization group (RG) in quantum field theory (QFT). In the first part we study the structure of RG flows in general Poincaré-invariant, unitary QFTs, and in particular the irreversibility properties and the rel ...

EPFL2016

Scaling laws for jets of single cavitation bubbles

Mohamed Farhat, Nicolas Dorsaz, Danail Obreschkow, Philipp Kobel, Outi Supponen, Marc Tinguely

Fast liquid jets, called micro-jets, are produced within cavitation bubbles experiencing an aspherical collapse. Here we review micro-jets of different origins, scales and appearances, and propose a unified framework to describe their dynamics by using an ...

Cambridge University Press2016

Dynamics of the head of gravity currents

Mário Jorge Rodrigues Pereira Da Franca, Helena Isabel Dos Santos Nogueira, Claudia Adduce

The present work experimentally investigates the dynamics of unsteady gravity currents produced by lock-release of a saline mixture into a fresh water tank. Seven different experimental runs were performed by varying the density of the salinemixture in the ...

Springer Verlag2013

Cosmological constraints on Lorentz violating dark energy

Julien Lesgourgues, Sergey Sibiryakov, Diego Blas Temino, Benjamin Audren

The role of Lorentz invariance as a fundamental symmetry of nature has been lately reconsidered in different approaches to quantum gravity. It is thus natural to study whether other puzzles of physics may be solved within these proposals. This may be the c ...

Iop Publishing Ltd2013

Stochastic Exploration of Ambiguities for Non-Rigid Shape Recovery

Pascal Fua

Recovering the 3D shape of deformable surfaces from single images is known to be a highly ambiguous problem because many different shapes may have very similar projections. This is commonly addressed by restricting the set of possible shapes to linear comb ...

Institute of Electrical and Electronics Engineers2013

Tackling the Supersymmetric Flavour Problem in String Models

Christopher John Andrey

In this work we address one of the phenomenological issues of beyond the Standard Model scenarios which embed Supersymmetry, namely the Supersymmetric Flavour Problem, in the context of String Theory. Indeed, the addition of new interactions to the Standar ...

EPFL2011