Éditions philosophiques
Nonlinear fourth order Taylor expansion of lattice Boltzmann schemes
We propose a formal expansion of multiple relaxation times lattice Boltzmann schemes in terms of a single infinitesimal numerical variable. The result is a system of partial differential equations for the conserved moments of the lattice Boltzmann scheme. The expansion is presented in the nonlinear case up to fourth order accuracy. The asymptotic c...
Probing nuclear effects with neutrino-induced charged-current neutral pion production
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We study neutrino-induced charged-current (CC) $\pi^0$ production on carbon nuclei using events with fully imaged final-state proton-$\pi^0$ systems. Novel use of final-state correlations based on transverse kinematic imbalance enable the first measurements of the struck nucleon's Fermi motion, of the intranuclear momentum transfer (IMT) dynamics, ...
Testing the accuracy of qubit rotations on a public quantum computer
Published in Frontiers in Physics
We analyze the results of the test of π/2 qubit rotations on a public quantum computer provided by IBM. We measure a single qubit rotated by π/2 about a random axis, and we accumulate vast statistics of the results. The test performed on different devices shows systematic deviations from the theoretical predictions, which appear at level 10–3. Some...
Isolation of squares in graphs
Given a set $\mathcal{F}$ of graphs, we call a copy of a graph in $\mathcal{F}$ an $\mathcal{F}$-graph. The $\mathcal{F}$-isolation number of a graph $G$, denoted by $\iota(G,\mathcal{F})$, is the size of a smallest subset $D$ of the vertex set $V(G)$ such that the closed neighbourhood of $D$ intersects the vertex sets of the $\mathcal{F}$-graphs c...
Risk Aversion and Insurance Propensity
We provide a new foundation of risk aversion by showing that the propension to exploit insurance opportunities fully describes this attitude. Our foundation, which applies to any probabilistically sophisticated preference, well accords with the commonly held prudential interpretation of risk aversion that dates back to the seminal works of Arrow (1...
The Secret Geographer: Thinking Aloud on Legal Engagements in Scholar-Activism
The award-winning and best-selling book The Secret Barrister (2018) took the general public into the unfamiliar space of the courtroom. Inspired both by its candour and illumination of the legal world and its proceedings, this roundtable reveals some of the hidden stories of geographers, including ourselves, who are engaged in scholar-activism in l...
Characterization of the BOLDPET optical prototype, an innovative Cherenkov detector for 511 keV γ radiation
Published in Journal of Instrumentation
In the present work we describe the design, construction, and testing of the optical prototype developed for the BOLDPET project, with the objective of creating a PET detection module with high spatial and time resolution. The BOLDPET technology uses an innovative detection liquid, trimethylbismuth, for detecting 511 keV γ-quanta resulting from pos...
A tree-cotree splitting for the construction of divergence-free finite elements: the high-order case
We extend, to Raviart-Thomas finite elements of any degree, two methods for the construction of basis of the space of divergence-free functions that are well established in the case of degree one. The first one computes directly a basis of the kernel of the divergence operator whereas the second one computes a basis of the image of the curl operato...
Electro-Gravity Via Geometric Chronon Field and on the origin of mass
In 1982, Dr. Sam Vaknin pondered the idea of reconstructing physics based on time as a field. His idea appeared in his doctorate dissertation as an amendment to the Dirac spinor equation. Sam saw the Quantum Field Theory particles and momentum and energy as a result of the language of physics and of the way the human mind perceives reality and not ...
