Forward and backwards search for latex source and their compiled images is a must have feature for me.
Category Archive: Uncategorized
Hyperbolicity of BSSN
So, from what I understand it seems that strong and symmetric hyperbolicity of equations is only defined for systems with first order derivatives. The significance is that strong or symmetric hyperbolic systems of differential equations are “well posed” that is, roughly speaking, that they have unique solutions that depend continuously on the initial data (i.e. …
MOND v LambdaCDM
I have a soft spot for MOND. Yes, it’s a silly sounding name but I kind of like it. I must admit that this is because CDM feels a bit contrived. The CDM models requires dwarf galaxies to be missing approximately 99% of the baryons associated to their dark matter halo. A bit unnecessary perhaps? …
Summation by parts (SBP) operators and interface boundary treatments
Finished of Carpenter, Nordstrom and Gottlieb’s paper, “A stable and conservative interface treatment of arbitrary spatial accuracy”. I like papers like this. It ‘feels’ clean, organised self contained. Writing such papers takes work so when I find ones like this I take a bit more time over them. The crux of the paper is a …
Rate of convergence not affected by lower order convergence near boundaries
I’ve just finished up my second reading of Gustafsson’s, “The convergence rate for difference approximations to mixed initial boundary value problems” and I’m still abit confused. The paper is referenced by (what seems to me) almost everyone and their dog as justification that a finite difference scheme can have one order of convergence less on …