Publications associées à Consistent Extension of Horava 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

Ultra-high quantum coherent and scalable superconducting circuit optomechanics, from topological lattices to quantum storage

Amir Youssefi

Mechanical oscillators can exhibit modes with ultra-low energy dissipation and compact form factors due to the slow velocity of acoustic waves, and are already used in applications ranging from timing to wireless filters. Over the past decade, novel ways i ...

EPFL2024

Scale invariant Einstein-Cartan gravity and flat space conformal symmetry

Mikhail Chapochnikov, Georgios Karananas, Sebastian Zell

We find the conditions under which scale-invariant Einstein-Cartan gravity with scalar matter fields leads to an approximate conformal invariance of the flat space particle theory up to energies of the order of the Planck mass. In the minimal setup, these ...

Springer Nature2023

Void Lensing in Cubic Galileon Gravity

Huanyuan Shan, Jiaxi Yu, Qiao Wang, Cheng Zhao, Jun Zhang

Weak-lensing studies via cosmic voids are a promising probe of modified gravity (MG). The excess surface mass density (ESD) is widely used as a lensing statistic in weak-lensing research. In this paper, we use the ray-tracing method to study the ESD around ...

IOP Publishing Ltd2023

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

Exact quantum conformal symmetry, its spontaneous breakdown, and gravitational Weyl anomaly

Mikhail Chapochnikov, Anna Tokareva

The classical Lagrangian of the Standard Model enjoys the symmetry of the full conformal group if the mass of the Higgs boson is put to zero. This is a hint that conformal symmetry may play a fundamental role in the ultimate theory describing nature. The o ...

American Physical Society2023

Universality of loop corrected soft theorems in 4d

Biswajit Sahoo

In [1], logarithmic correction to subleading soft photon and soft graviton theorems have been derived in four spacetime dimensions from the ratio of IR-finite S-matrices. This has been achieved after factoring out IR-divergent components from the tradition ...

Springer Nature2023

Anomaly-free scale symmetry and gravity

Mikhail Chapochnikov, Anna Tokareva

In this Letter, we address the question of whether the conformal invariance can be considered as a global symmetry of a theory of fundamental interactions. To describe Nature, this theory must contain a mechanism of spontaneous breaking of the scale symmet ...

ELSEVIER2023

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

Coupling metric-affine gravity to a Higgs-like scalar field

Sebastian Zell

General relativity (GR) exists in different formulations. They are equivalent in pure gravity but generically lead to distinct predictions once matter is included. After a brief overview of various versions of GR, we focus on metric-affine gravity, which a ...

American Physical Society2022

Cosmology with Large Scale Structures using Massive Spectroscopic Surveys

Amélie Tamone

Spectroscopic surveys aim to map large fractions of the Universe to study the Large Scale Structures (LSS). LSS evolution traces the distribution of matter as a result of the tension between the expansion of the Universe and the gravitational forces, which ...

EPFL2022

A simple theoretical model for estimating the frequency characteristics of black hole mergers

Roberto Guarino

Gravitational waves, despite predicted within the Theory of General Relativity about a century ago, were observed experi-mentally only in the last few years, thanks to the recent advances of the LIGO and Virgo detectors. In this work, we introduce a simple ...

2022

Gravitational causality and the self-stress of photons

Giulia Isabella, Brando Bellazzini

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

Nonperturbative Quantum Field Theory in Curved Spacetime

Kamran Salehi Vaziri

Quantum Field Theory(QFT) as one of the most promising frameworks to study high energy and condensed matter physics, has been mostly developed by perturbative methods. However, perturbative methods can only capture a small island of the space of QFTs. QFT ...

EPFL2022

Semiclassical methods in conformal field theories scrutinized by the epsilon-expansion

Gil Badel

Conformal Field Theories (CFTs) are crucial for our understanding of Quantum Field Theory (QFT). Because of their powerful symmetry properties, they play the role of signposts in the space of QFTs. Any method that gives us information about their structure ...

EPFL2022

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

Probing gravity with the DES-CMASS sample and BOSS spectroscopy

Eduardo Sanchez, Jonathan Andrew Blazek

The DES-CMASS sample (DMASS) is designed to optimally combine the weak lensing measurements from the Dark Energy Survey (DES) and redshift-space distortions (RSD) probed by the CMASS galaxy sample from the Baryonic Oscillation Spectroscopic Survey. In this ...

2022

Testing general relativity on cosmological scales at redshift z similar to 1.5 with quasar and CMB lensing

Cheng Zhao

We test general relativity (GR) at the effective redshift (z) over tilde similar to 1.5 by estimating the statistic E-G, a probe of gravity, on cosmological scales 19 - 190 h(-1)Mpc. This is the highest redshift and largest scale estimation of E-G so far. ...

OXFORD UNIV PRESS2021

Nonperturbative Mellin Amplitudes

João Pedro Alves Da Silva

Conformal field theory lies at the heart of two central topics in theoretical high energy physics: the study of quantum gravity and the mapping of quantum field theories through the renormalization group. In this thesis we explore a technique to study conf ...

EPFL2021