Publications associées à History of Lorentz transformations

Quadrupolar susceptibility modeling of substrated metasurfaces with application to the generalized Brewster effect

Olivier Martin, Karim Achouri, Ville Tuovi Tiukuvaara

We derive generalized sheet transition conditions (GSTCs) including dipoles and quadrupoles, using generalized functions (distributions). This derivation verifies that the GSTCs are valid for metasurfaces in non-homogeneous environments, such as for practi ...

Optica Publishing Group2023

Preliminary design of the cold mass supports for the EU DEMO feeders

Kamil Sedlák, Roberto Guarino

The Cold Mass Support (CMS) is a basic structural component of the feeder system of the EU DEMO tokamak. The function of this structural element is not only to provide support to the containment duct - wiring the cryogenic lines, electrical bus bars and in ...

2023

AC loss and electrical resistance of the RW3 diffusion-bonded joint

Vincenzo D'Auria

For the European DEMO fusion reactor, several options of the Toroidal Field (TF) coil design were proposed. The winding of the TF coil option 1 is based on React&Wind (RW), Nb3Sn, graded conductors in order to optimize the amount of superconductor accordin ...

2023

Metasurface Near-Field Measurements with Incident Field Reconstruction Using a Single Horn Antenna

Shourya Dutta Gupta, Ville Tuovi Tiukuvaara

Metasurfaces (MSs) are the 2-D equivalent of metaterials, the latter being a class of artificial engineered materials exhibiting peculiar electromagnetic properties [1], [2]. Generally constructed as arrays of deeply sub-wavelength resonant particles on a ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022

Dipole polarizability of time-varying particles

Romain Christophe Rémy Fleury, Theodoros Koutserimpas, Mohammad Sajjad Mirmoosa

Invariance under time translation (or stationarity) is probably one of the most important assumptions made when investigating electromagnetic phenomena. Breaking this assumption is expected to open up novel possibilities and result in exceeding conventiona ...

2022

High-sensitivity mapping of magnetic induction fields with nanometer-scale resolution: comparison of off-axis electron holography and pixelated differential phase contrast

Jean-Luc Rouvière, Victor Carle Adrien Boureau

We compare two transmission electron microscopy (TEM) based techniques that can provide highly spatially resolved quantitative measurements of magnetic induction fields at high sensitivity. To this end, the magnetic induction of a ferromagnetic NiFe nanowi ...

IOP PUBLISHING LTD2021

Implications of ANEC for SCFTs in four dimensions

Andrea Manenti, Alessandro Vichi

We explore consequences of the Averaged Null Energy Condition (ANEC) for scaling dimensions Delta of operators in four-dimensional N = 1 superconformal field theories. We show that in many cases the ANEC bounds are stronger than the corresponding unitarity ...

Springer Nature2020

Crack front waves: A 3D dynamic response to a local perturbation of tensile and shear cracks

Jean-François Molinari, Fabian Barras, Damien Spielmann, Fatima-Ezzahra Fekak

Crack front waves are long-lived perturbations propagating along the crack front. They are triggered by heterogeneities on the crack plane, as for instance tough asperities, which disturb the crack front shape. Crack front waves are thought to leave a trac ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Generalization of the Haldane conjecture to SU(n) chains

Frédéric Mila, Miklos Lajko

Recently, SU(3) chains in the symmetric and self-conjugate representations have been studied using field theory techniques. For certain representations, namely rank-psymmetric ones with pnot a multiple of 3, it was argued that the ground state exhibits gap ...

2020

Shapes From Echoes: Uniqueness From Point-to-Plane Distance Matrices

Martin Vetterli, Ivan Dokmanic, Miranda Krekovic

We study the problem of localizing a configuration of points and planes from the collection of point-to-plane distances. This problem models simultaneous localization and mapping from acoustic echoes as well as the & x201C;structure from sound & x201D; app ...

2020

Spinning operators and defects in conformal field theory

Marco Meineri

We study the kinematics of correlation functions of local and extended operators in a conformal field theory. We present a new method for constructing the tensor structures associated to primary operators in an arbitrary bosonic representation of the Loren ...

Springer Nature2019

Fermion conformal bootstrap in 4d

Denis Karateev, Alessandro Vichi

We apply numerical conformal bootstrap techniques to the four-point function of a Weyl spinor in 4d non-supersymmetric CFTs. We find universal bounds on operator dimensions and OPE coefficients, including bounds on operators in mixed symmetry representatio ...

Springer Nature2019

Extensive amenability and an application to interval exchanges

Nicolas Monod, Nicolas Matte Bon

Extensive amenability is a property of group actions which has recently been used as a tool to prove amenability of groups. We study this property and prove that it is preserved under a very general construction of semidirect products. As an application, w ...

2018

On massive Nambu-Goldstone fields

Andrey Shkerin

We consider two theories undergoing the same spontaneous symmetry breaking pattern but with different representations of an order parameter under the Lorentz group. The effective description of the first theory includes a massive Nambu-Goldstone field, whi ...

EDP SCIENCES2018

Vector-Based 3D Graphic Statics: Transformations of Force Diagrams

Corentin Jean Dominique Fivet, Pierluigi D'Acunto

The reciprocity between form and force diagrams in 2D graphic statics makes it possible to manipulate the form diagram while directly evaluating the redistribution of the forces within the force diagram. Conversely, after modifying the force diagram, the c ...

2017

The relativistic foundations of synchrotron radiation

Giorgio Margaritondo

Special relativity (SR) determines the properties of synchrotron radiation, but the corresponding mechanisms are frequently misunderstood. Time dilation is often invoked among the causes, whereas its role would violate the principles of SR. Here it is show ...

International Union of Crystallography (IUCr)2017

Constraints on violation of Lorentz invariance from atmospheric showers initiated by multi-TeV photons

Sergey Sibiryakov

Parameterizing hypothetical violation of Lorentz invariance at high energies using the framework of effective quantum field theory, we discuss its effect on the formation of atmospheric showers by very-high-energy gamma rays. In the scenario where Lorentz ...

Iop Publishing Ltd2017

Concept and Applications of Extents in Chemical Reaction Systems

Dominique Bonvin, Julien Léo Billeter, Michael Amrhein, Sriniketh Srinivasan, Diogo Filipe Mateus Rodrigues

Models of chemical reaction systems can be quite complex as they typically include information regarding the reactions, the various transfers of heat and mass, as well as the effects of the inlet and outlet flows. It is well known that a linear transformat ...

2017

Poincaré, Scale and Conformal Symmetries : Gauge Perspective and Cosmological Ramifications

Georgios Karananas

Symmetries are omnipresent and play a fundamental role in the description of Nature. Thanks to them, we have at our disposal nontrivial selection rules that dictate how a theory should be constructed. This thesis, which is naturally divided into two parts, ...

EPFL2016

From Scale Invariance to Lorentz Symmetry

Sergey Sibiryakov

It is shown that a unitary translationally invariant field theory in 1 + 1 dimensions, satisfying isotropic scale invariance, standard assumptions about the spectrum of states and operators, and the requirement that signals propagate with finite velocity, ...

Amer Physical Soc2014