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Concept

Groupe de Poincaré (transformations)

Publications associées (28)

Symmetry-reduced low-dimensional representation of large-scale dynamics in the asymptotic suction boundary layer

Omid Ashtari

An important feature of turbulent boundary layers are persistent large-scale coherent structures in the flow. Here, we use Dynamic Mode Decomposition (DMD), a data-driven technique designed to detect spatio-temporal coherence, to construct optimal low-dime ...

Elsevier2023

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

Implications of ANEC for SCFTs in four dimensions

Alessandro Vichi, Andrea Manenti

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

Large charge, semiclassics and superfluids : from broken symmetries to conformal field theories

Gabriel Francisco Cuomo

This thesis explores the application of semiclassical methods in the study of states with large quantum numbers for theories invariant under internal symmetries. In the first part of the thesis, we study zero-temperature superfluids. These provide a gener ...

EPFL2020

Non-Abelian reciprocal braiding of Weyl points and its manifestation in ZrTe

Oleg Yazyev, Quansheng Wu

Weyl points in three-dimensional systems with certain symmetry carry non-Abelian topological charges, which can be transformed via non-trivial phase factors that arise upon braiding these points inside the reciprocal space. ...

NATURE PUBLISHING GROUP2020

Fermion conformal bootstrap in 4d

Alessandro Vichi, Denis Karateev

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

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

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

Time reversal and symmetries of time correlation functions

Sara Bonella, Alessandro Coretti

The time reversal invariance of classical dynamics is reconsidered in this paper with specific focus on its consequences for time correlation functions and associated properties such as transport coefficients. We show that, under fairly common assumptions ...

Taylor & Francis2018

Rotation Invariance and Directional Sensitivity: Spherical Harmonics versus Radiomics Features

Michaël Unser, Julien René Fageot, John Paul Ward, Adrien Raphaël Depeursinge

We define and investigate the Local Rotation Invariance (LRI) and Directional Sensitivity (DS) of radiomics features. Most of the classical features cannot combine the two properties, which are antagonist in simple designs. We propose texture operators bas ...

SPRINGER INTERNATIONAL PUBLISHING AG2018

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

Search for Violations of Lorentz Invariance and CPT Symmetry in B-(s)(0) Mixing

Jian Wang, Olivier Schneider, Zhirui Xu, Yiming Li, Yi Zhang, Lei Zhang, Aurelio Bay, Guido Haefeli, Jessica Prisciandaro, Tatsuya Nakada, Christoph Frei, Mark Tobin, Frédéric Blanc, Minh Tâm Tran, Michel De Cian, Greig Alan Cowan, Maurizio Martinelli, Donal Patrick Hill, Liang Sun, Pietro Marino, Luca Pescatore, François Fleuret, Mirco Dorigo, Jean Wicht, Sebastiana Gianì, Liupan An, Elena Graverini, Federico Leo Redi, Chitsanu Khurewathanakul, Ilya Komarov, Renato Quagliani, Maxime Schubiger, Hang Yin, Guido Andreassi, Bastien Luca Muster, Violaine Bellée, Maria Vieites Diaz, Olivier Göran Girard, Axel Kuonen, Alessandro Mapelli

Violations of CPT symmetry and Lorentz invariance are searched for by studying interference effects in B-0 mixing and in B-s(0) mixing. Samples of B-0 -> J/psi K-S(0) and B-0(s) -> J/psi K+K- decays are recorded by the LHCb detector in proton-proton collis ...

Amer Physical Soc2016

Multisymplectic variational integrators and space/time symplecticity

Tudor Ratiu, François Gay-Balmaz, François Marie Alain Demoures

Multisymplectic variational integrators are structure-preserving numerical schemes especially designed for PDEs derived from covariant spacetime Hamilton principles. The goal of this paper is to study the properties of the temporal and spatial discrete evo ...

World Scientific Publ Co Pte Ltd2016

Spontaneously broken mass

Solomon G Shamsuddin Osman Endlich

The Galilei group involves mass as a central charge. We show that the associated superselection rule is incompatible with the observed phenomenology of superfluid helium 4: this is recovered only under the assumption that mass is spontaneou.519 broken. Thi ...

Springer Nature2015

The particle spectrum of parity-violating Poincare gravitational theory

Georgios Karananas

In this paper we investigate the physical spectrum of the gravitational theory based on the Poincare group with terms that are at most quadratic in tetrad and spin connection, allowing for the presence of parity-even as well as parity-odd invariants. We de ...

Iop Publishing Ltd2015

Cosmological constraints on deviations from Lorentz invariance in gravity and dark matter

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

We consider a scenario where local Lorentz invariance is violated by the existence of a preferred time direction at every space-time point. This scenario can arise in the context of quantum gravity and its description at low energies contains a unit time-l ...

Iop Publishing Ltd2015

General coordinate invariance in quantum many-body systems

Alexander Monin, Solomon G Shamsuddin Osman Endlich

We extend the notion of general coordinate invariance to many-body, not necessarily relativistic, systems. As an application, we investigate nonrelativistic general covariance in Galilei-invariant systems. The peculiar transformation rules for the backgrou ...

American Physical Society2014

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

Alexander Monin, Francesco Riva, 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

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

The Holder-Poincaré duality for Lqp-cohomology

Marc Troyanov

We prove the following version of Poincaré, duality for reduced L (q,p) -cohomology: For any 1 < q, p < a, the Lqp -cohomology of a Riemannian manifold is in duality with the interior Lp'q'-cohomology for 1/p + 1/p' = 1/q + 1/q' = 1. ...

Springer Netherlands2012