This paper constructs multirate linear multistep time discretizations based on Adams-Bashforth methods. These methods are aimed at solving conservation laws and allow different timesteps to be used in different parts of the spatial domain. The proposed family of discretizations is second order accurate in time and has conservation and linear and nonlinear stability properties under local CFL co...

This paper constructs multirate time discretizations for hyperbolic conservation laws that allow different timesteps to be used in different parts of the spatial domain. The proposed family of discretizations is second order accurate in time and has conservation and linear and nonlinear stability properties under local CFL conditions. Multirate timestepping avoids the necessity to take small gl...

We give in this note a generalisation of the following theorem of Henkin and Passare (cf. [7] and [8]) : Let be Y an analytic subvariety of pure codimension p in a linearly p−concave domain U , and ω a meromorphic q−form (q > 0) on Y ; if the Abel-Radon transform R(ω ∧ [Y ]), which is meromorphic on U * , has a meromorphic prolongation tõ U * containing U * , then Y extends as an analytic subva...

In this paper we define Courant algebroids in a purely algebraic way and study their deformation theory by using two different but equivalent graded Poisson algebras of degree −2.

We show that quasi-Poisson structures can be identified with Dirac structures in suitable Courant algebroids. This provides a geometric way to construct Lie algebroids associated with quasi-Poisson spaces.

We show that for any odd k and any instance = of the Max-kXOR constraint satisfaction problem, there is an efficient algorithm that finds an assignment satisfying at least a 1 2 + Ω(1/ √ D) fraction of =’s constraints, where D is a bound on the number of constraints that each variable occurs in. This improves both qualitatively and quantitatively on the recent work of Farhi, Goldstone, and Gutm...

Numerical time-step limitations associated with the explicit treatment of advection-dominated problems in computational uid dynamics are often relaxed by employing Eulerian-Lagrangian methods. These are also known as semi-Lagrangian methods in the atmospheric sciences. Such methods involve backward time integration of a characteristic equation to nd the departure point of a uid particle arrivin...