Before leaving IAS I talked with David Weinberg about a project I had in mind to try and leverage the stringyness or filamentarity of LSS to get an independent set of constraints on the cosmological parameters, most notably $\sigma_8$. He told me lots of people have gone down this dark dark path, but he also said my proposed observable was different than any he'd heard of and it was worth checking to see if it helps. He said to keep the study focussed and just try and see if I can use it to break the $\sigma_8$ degeneracy with $\Omega_m$. Most importantly, don't get lost in trying to define what a filament is, or characterize its profile and that sort of thing, because those things do not seem to be observationally tractable as yet.
I talk to Salman, to see if they have any halo catalogs from sims with different values of these two parameters, with degenerate power spectra. He suspected not. They did do parameter scans, but did not specifically try and generate degenerate power spectra. He suggested I use the emulator (newest version is HERE) they have developed to find two cosmologies that I want, and they would do the sims and give me some halo catalogs. I need to think about what would be best regarding the size versus the resolution of the sims. Maybe the best thing would be to use one of their existingsims, and just have them run the degenerate twin. For this, however, I would need the CPs for one of the ones they used. Maybe they use WMAP as one of the fiducial runs??
