188 citations · 747 across the 28 of their papers we have counts for
29 papers
Programmable Compute-in-Transit using Integrated Photonics
Imon Kundu, Livi Hammond, Jamie Todd +8
Modern hardware designs for AI and cryptography treat data transit and processing separately. At Optalysys we have demonstrated programmable Photonic hardware that computes mathema…
ICLR 2021 Challenge for Computational Geometry & Topology: Design and Results
Nina Miolane, Matteo Caorsi, Umberto Lupo +30
This paper presents the computational challenge on differential geometry and topology that happened within the ICLR 2021 workshop "Geometric and Topological Representation Learning…
Optical Convolutional Neural Networks -- Combining Silicon Photonics and Fourier Optics for Computer Vision
Edward Cottle, Florent Michel, Joseph Wilson +2
The Convolutional Neural Network (CNN) is a state-of-the-art architecture for a wide range of deep learning problems, the quintessential example of which is computer vision. CNNs p…
Parametrized Path Approach to Vacuum Decay
Florent Michel
We develop a new real-time approach to vacuum decay based on a reduction to a finite number of degrees of freedom. The dynamics is followed by solving a generalized Schrödinger equ…
Simulating seeded vacuum decay in a cold atom system
Thomas P. Billam, Ruth Gregory, Florent Michel +1
We propose to test the concept of seeded vacuum decay in cosmology using an analogue gravity Bose-Einstein condensate system. The role of the nucleation seed is played by a vortex…
Gravitational Effects in g Factor Measurements and High-Precision Spectroscopy: Limits of Einstein's Equivalence Principle
Ulrich D. Jentschura
We study the interplay of general relativity, the equivalence principle, and high-precision experiments involving atomic transitions and g factor measurements. In particular, we de…
Relativistic collapse of axion stars
Florent Michel, Ian G. Moss
We study the gravitational collapse of an axion field in null coordinates, assuming spherical symmetry. Compared with previous studies, we use a simpler numerical scheme which can…
Nonlinearities induced by parametric resonance in effectively 1D atomic Bose condensates
Scott Robertson, Florent Michel, Renaud Parentani
We present a numerical study of the dynamical effects following a sudden change of the transverse trapping frequency in an elongated Bose-Einstein condensate, which induces periodi…
Gravity waves on modulated flows downstream from an obstacle: The transcritical case
Florent Michel, Renaud Parentani, Scott Robertson
Periodic spatial variations of some parameter arise in analogue gravity experiments aimed at detecting the analogue version of the Hawking effect in a white hole flow. Having the s…
Excited cosmic strings with superconducting currents
Betti Hartmann, Florent Michel, Patrick Peter
We present a detailed analysis of {\it excited} cosmic string solutions which possess superconducting currents. These currents can be excited inside the string core, and - if the c…
Nonlinear and quantum effects in analogue gravity
Florent Michel
The present thesis deals with some properties of classical and quantum scalar fields in an inhomogeneous and/or time-dependent background, focusing on models where the latter can b…
Assessing degrees of entanglement of phonon states in atomic Bose gases through the measurement of commuting observables
Scott Robertson, Florent Michel, Renaud Parentani
We show that measuring commuting observables can be sufficient to assess that a bipartite state is entangled according to either nonseparability or the stronger criterion of 'steer…
Controlling and observing nonseparability of phonons created in time-dependent 1D atomic Bose condensates
Scott Robertson, Florent Michel, Renaud Parentani
We study the spectrum and entanglement of phonons produced by temporal changes in homogeneous one-dimensional atomic condensates. To characterize the experimentally accessible chan…
Radial excitations of current-carrying vortices
Betti Hartmann, Florent Michel, Patrick Peter
We report on the existence of a new type of cosmic string solutions in the Witten model with U(1)xU(1) symmetry. These solutions are superconducting with radially excited condensat…
Phonon spectrum and correlations in a transonic flow of an atomic Bose gas
Florent Michel, Jean-François Coupechoux, Renaud Parentani
Motivated by a recent experiment of J.~Steinhauer, we reconsider the spectrum and the correlations of the phonons spontaneously emitted in stationary transonic flows. The latter ar…
Scattering of gravity waves in subcritical flows over an obstacle
Scott Robertson, Florent Michel, Renaud Parentani
We numerically study the scattering coefficients of linear water waves on stationary flows above a localized obstacle. We compare the scattering on trans- and subcritical flows, an…
Dynamical instabilities and quasi-normal modes, a spectral analysis with applications to black-hole physics
Antonin Coutant, Florent Michel, Renaud Parentani
Black hole dynamical instabilities have been mostly studied in specific models. We here study the general properties of the complex-frequency modes responsible for such instabiliti…
Observation of noise correlated by the Hawking effect in a water tank
L. -P. Euvé, F. Michel, R. Parentani +2
We measured the power spectrum and two-point correlation function for the randomly fluctuating free surface on the downstream side of a stationary flow with a maximum Froude number…
No hair theorems for analogue black holes
Florent Michel, Renaud Parentani, Robin Zegers
We show that transonic one dimensional flows which are analogous to black holes obey no-hair theorems both at the level of linear perturbations and in non-linear regimes. Consideri…
Mode mixing in sub- and trans-critical flows over an obstacle: When should Hawking's predictions be recovered?
Florent Michel, Renaud Parentani
We reexamine the scattering coefficients of shallow water waves blocked by a stationary counter current over an obstacle. By considering series of background flows, we show that th…
Black hole radiation in the presence of a universal horizon
Florent Michel, Renaud Parentani
In Hořava and Einstein-Æther theories of modified gravity, in spite of the violation of Lorentz invariance, spherically-symmetric stationary black hole solutions possess an inner u…
Slow Sound in a duct, effective transonic flows and analogue black holes
Yves Aurégan, Pierre Fromholz, Florent Michel +2
We propose a new system suitable for studying analogue gravity effects, consisting of a gas flowing in a duct with a compliant wall. Effective transonic flows are obtained from uni…
Non-linear effects in time-dependent transonic flows: An analysis of analogue black hole stability
Florent Michel, Renaud Parentani
We study solutions of the one-dimensional Gross-Pitaevskii equation to better understand dynamical instabilities occurring in flowing atomic condensates. Whereas transonic stationa…
Wave blocking and partial transmission in subcritical flows over an obstacle
Léo-Paul Euvé, Florent Michel, Renaud Parentani +1
We study and measure the transmission coefficient of counter-propagating shallow-water waves produced by a wave generator and scattered by an obstacle. To precisely compare theoret…