Todays and yesterday lectures at Nordita for our #COSMOMAG school:
connecting linear and non-linear stages of cosmic structure formation to potential impact of primordial magnetic fields on halo formation and their clustering.
@franco_vazza Interesting. I’m not sure I understand why you can just add a magntic Jean’s length like that.
If I remember, if you had a stand alone big cloud of gas and perturbed it, you need to balance the time it takes the pressure wave to move across and restore the collapse with pressure with the time scale of the gravitational in fall.
I guess if there is a magntic field that means there are charged particles around, but is the process of “squeezing” that blob of fields and the resulting stiffness act in similar way to a wave resisting the infall?
(Not an expert in this stuff)
@ChrisWalter I think I should have added them in quadrature, i.e. λ~(λgas^2+λB^2)^1/2 considering that they should approximately scale like λgas propto P^1/2 and λB propto PB^1/2, and it makes more sense to add Pressure to get the total effective pressure, rather than adding the sound + Alfven velocity.
(at least, just to give the approximate logic of it, reality is more complex, k-dependent and also non-linearly depending on the topology of B).
thanks!
