Finite-volume schemes developed in the meteorological community that permit long time steps are considered. These include Eulerian flux-form schemes as well as fully two-dimensional and cascade cellintegrated semi-Lagrangian (CISL) schemes. A oneand two-dimensional Von Neumann stability analysis of these finite-volume advection schemes is given. Contrary to previous analysis, no simplifications...

Using a generalisation of the detailed balance for systems maintained out of equilibrium by contact with 2 reservoirs at unequal temperatures or at unequal densities, we recover the fluctuation theorem for the large deviation funtion of the current. For large diffusive systems, we show how the large deviation funtion of the current can be computed using a simple additivity principle. The validi...

Le courant électrique est susceptible de léser tout tissu de l'organisme rencontré lors de son passage, de manière transitoire ou définitive. Les hémorragies cérébro-méningées secondaires à un accident d'électrisation par courant électrique à haute tension sont très rarement rapportées dans la littérature. Nous rapportons un cas d'hémorragie cérébro-méningée révélée par des manifestations neuro...

This note aims to demonstrate that every parabolic geometry has a naturally defined per-Courant algebröıd structure. If the geometry is regular, this structure is a Courant algebröıd if and only if the the curvature κ of the Cartan connection vanishes. This note assumes familiarity with both parabolic geometry, and Courant algebröıds. See [ČS00] and [ČG02] for a good introduction to the first c...

In this paper, we present two different techniques to accelerate and approximate particle-based fluid simulations. The first technique identifies and employs larger time steps than dictated by the CFL condition. The second introduces the concept of approximation in the context of particle advection. For that, the fluid is segregated into active and inactive particles, and a significant amount o...

We prove that pseudorandom sets in Grassmann graph have near-perfect expansion as hypothesized in [4]. This completes the proof of the 2-to-2 Games Conjecture (albeit with imperfect completeness) as proposed in [15, 3], along with a contribution from [2, 14]. The Grassmann graph Grglobal contains induced subgraphs Grlocal that are themselves isomorphic to Grassmann graphs of lower orders. A set...

In this note, we present a natural proof of a recent and surprising result of Gregory Berkolaiko interpreting the Courant nodal defect as a Morse index. This proof is inspired by a nice paper of Miroslav Fiedler published in 1975.

Many applications benefit from the ability to monitor the value of conditions over large, possibly distributed data sets. However, mechanisms to achieve this typically impose a performance overhead that the owners and users of such systems may be unwilling to accept. A compromise solution is to allow system owners to decide at what times they will allow computational resources to be given over ...

When one solves PDEs modelling physical phenomena, it is of great importance to take physical constraints into account. More precisely, numerical schemes have to be designed such that discrete solutions satisfy the same constraints as exact solutions. For instance, the underlying physical assumptions for the Euler equations are the positivity of both density and pressure variables. We consider ...

Let S be a closed *-derivation on a commutative C*-algebra M, suppose that ^ n = f l l = , D(8 ) is dense in si for some n = 1, 2 , . . . , oo, and let H:$4n^>si be a linear operator satisfying the locality condition supp(H/)cSupp(/), festn. It is shown that H =JJ p m=0 lm8 m on s£2m for some finite integer p<n and functions lm on X. Estimates on the coefficients lm are obtained and applied to ...