Publications associées à Theoretical gravity

Anomaly-free scale symmetry and gravity

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

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

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

Characterizing human mobility patterns in rural settings of sub-Saharan Africa

Andrea Rinaldo, Theophile Mande, Francisco Javier Perez Saez

Human mobility is a core component of human behavior and its quantification is critical for understanding its impact on infectious disease transmission, traffic forecasting, access to resources and care, intervention strategies, and migratory flows. When m ...

eLIFE SCIENCES PUBL LTD2021

Matter matters in Einstein-Cartan gravity

Mikhail Chapochnikov, Andrey Shkerin, Georgios Karananas, Sebastian Zell

We study scalar, fermionic and gauge fields coupled nonminimally to gravity in the Einstein-Cartan formulation. We construct a wide class of models with nondynamical torsion whose gravitational spectra comprise only themassless graviton. Eliminating nonpro ...

American Physical Society2021

Surface tension and viscosity of liquid Pd43Cu27Ni10P20 measured in a levitation device under microgravity

Roland Logé, Antonia Neels, Alex Dommann

Here we present measurements of surface tension and viscosity of the bulk glass-forming alloy Pd43Cu27Ni10P20 performed during containerless processing under reduced gravity. We applied the oscillating drop method in an electromagnetic levitation facility ...

Springer2019

Gravity-Independent Oscillate Boiling

Mohamed Farhat, Outi Supponen

Heat transfer in nucleate boiling relies on the detachment and rise of the boiling bubble, in which gravity plays the dominant role. Previous studies showed that in the absence of gravity, the bubble fails to rise, causing the dryout of the heater and sign ...

SPRINGER2019

Virtual Zero Gravity Impact on Internal Gravity Model

Ronan Boulic, Bruno Herbelin, Elisa Canzoneri

This project investigates the impact of a virtual zero gravity experience on the human gravity model. In the planned experiment, subjects are immersed with HMD and full body motion capture in a virtual world exhibiting either normal gravity or the apparent ...

Ieee Computer Soc2017

(Re-)inventing the relativistic wheel: gravity, cosets, and spinning objects

Francesco Riva, Alexander Monin, Solomon G Shamsuddin Osman Endlich

Space-time symmetries are a crucial ingredient of any theoretical model in physics. Unlike internal symmetries, which may or may not be gauged and/or spontaneously broken, space-time symmetries do not admit any ambiguity: they are gauged by gravity, and an ...

Springer Nature2014

The quest for the most spherical bubble: experimental setup and data overview

Mohamed Farhat, Nicolas Dorsaz, Danail Obreschkow, Philipp Kobel, Marc Tinguely, Aurèle De Bosset

We describe a recently realized experiment producing the most spherical cavitation bubbles today. The bubbles grow inside a liquid from a point plasma generated by a nanosecond laser pulse. Unlike in previous studies, the laser is focussed by a parabolic m ...

Springer Verlag2013

The effect of pressure gradient on the collapse of cavitation bubbles in normal and reduced gravity

Marc Tinguely

When water flows through hydraulic turbomachines, the local pressure can become low enough to vaporize the water and create vapor cavities. This phenomenon is called cavitation. When the cavities collapse, shock waves and liquid jets traveling through the ...

EPFL2013

Analysis of lock-exchange gravity currents over smooth and rough beds

Mário Jorge Rodrigues Pereira Da Franca, Claudia Adduce

Gravity currents produced by full-depth lock-release of saline water into a fresh water tank are studied focusing on the influence of the initial density of the saline mixture in the lock and the bed roughness on gravity current kinematics. Temporal evolut ...

Taylor & Francis Ltd2013