hi cosmo-torun
Cactus: numerical relativity cosmo workshop Fri 2 March @15.00 @KRA Jan Ostrowski
Jan is doing very interesting work in finding out how to do numerical relativity. One way of saying it is the following:
"Normal" cosmological N-body simulations consist of *Newtonian* gravity simulated on a highly simplified (perfectly homogeneous) relativistic "background". In formal scientific language, this is called a "heuristic" approach; in informal language, it's called "a fudge" - it's a mathematical shortcut that seems like it should work and lets us quickly compare some sort of "model" to observations instead of waiting 50 years for the mathematics to be solved. In principle, every scientist using the heuristic/fudge is aware of this. Pure theory is very difficult to apply to the real world.
Relativistic cosmological simulations should be "directly" relativistic, consistent with the Einstein equations, without using the heuristic/fudge of adding "perturbations" that obey Newtonian gravity to a relativistic "background". So these simulations can be called "background-free".
How can we do background-free cosmology simulations?
Jan will present a discussion on this.
pozdr boud
hello cosmo-torun
Could we start a little bit ealier, for example @14:00?
I have "dyżur" at control room starting at 16:00.
2012/2/29 Boud Roukema boud@astro.uni.torun.pl
hi cosmo-torun
Cactus: numerical relativity cosmo workshop Fri 2 March @15.00 @KRA Jan Ostrowski
Jan is doing very interesting work in finding out how to do numerical relativity. One way of saying it is the following:
"Normal" cosmological N-body simulations consist of *Newtonian* gravity simulated on a highly simplified (perfectly homogeneous) relativistic "background". In formal scientific language, this is called a "heuristic" approach; in informal language, it's called "a fudge" - it's a mathematical shortcut that seems like it should work and lets us quickly compare some sort of "model" to observations instead of waiting 50 years for the mathematics to be solved. In principle, every scientist using the heuristic/fudge is aware of this. Pure theory is very difficult to apply to the real world.
Relativistic cosmological simulations should be "directly" relativistic, consistent with the Einstein equations, without using the heuristic/fudge of adding "perturbations" that obey Newtonian gravity to a relativistic "background". So these simulations can be called "background-free".
How can we do background-free cosmology simulations?
Jan will present a discussion on this.
pozdr boud
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hi everyone,
On Wed, 29 Feb 2012, Tomasz Kazimierczak wrote:
Could we start a little bit ealier, for example @14:00?
Does anyone (especially Jan!) have a problem with starting at 14:00 ?
See everyone this afternoon :)
pozdr boud
I have "dyżur" at control room starting at 16:00.
2012/2/29 Boud Roukema boud@astro.uni.torun.pl hi cosmo-torun
Cactus: numerical relativity cosmo workshop Fri 2 March @15.00 @KRA Jan Ostrowski Jan is doing very interesting work in finding out how to do numerical relativity. One way of saying it is the following: "Normal" cosmological N-body simulations consist of *Newtonian* gravity simulated on a highly simplified (perfectly homogeneous) relativistic "background". In formal scientific language, this is called a "heuristic" approach; in informal language, it's called "a fudge" - it's a mathematical shortcut that seems like it should work and lets us quickly compare some sort of "model" to observations instead of waiting 50 years for the mathematics to be solved. In principle, every scientist using the heuristic/fudge is aware of this. Pure theory is very difficult to apply to the real world. Relativistic cosmological simulations should be "directly" relativistic, consistent with the Einstein equations, without using the heuristic/fudge of adding "perturbations" that obey Newtonian gravity to a relativistic "background". So these simulations can be called "background-free". How can we do background-free cosmology simulations? Jan will present a discussion on this. pozdr boud _______________________________________________ Cosmo-torun mailing list Cosmo-torun@cosmo.torun.pl http://cosmo.torun.pl/mailman/listinfo/cosmo-torun
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Boud Roukema -
Tomasz Kazimierczak