Carol's favourite topics
Carolina Cuesta-Lazaro
IAIFI Fellow (CfA/MIT)
1
Observe galaxies
4
Pick your favourite analytical likelihood (Gaussian!)
5
Compute ~1Million times to get posterior
Constrain cosmology 101
Missing Information!
Perturbation Theory inaccurate / hard to compute
Is it always true?
3
Work on your analytical theory
2
Count pairs as a function of distance
+ Galaxy formation
+ Observational systematics (Cut-sky, Fiber collisions)
+ Lightcone, Redshift Space Distortions....
Forward Model
N-body simulations
Observations
SIMBIG arXiv:2211.00723
Credit: Siddharth Mishra-Sharma
We can simulate the observable Universe, we just need hydrodynamical simulations
25 \, h^{-1}\mathrm{Mpc}
10^{10} - 10^{11} M_\odot
Super massive black hole seeding in dark matter halos
BH feedback impacts galactic scales
Black holes can also growth through mergers
they can even teleport!
Can ML bridge the scale gap to help us carry out full physics simulations across all scales?
Subresolution models
(Credit: http://tigress-web.princeton.edu/~changgoo/)
Resolving star formation
We can't model galaxy formation, how do we make our models robust?
Robust Summarisation
\mathcal{L} = I(S(x_\mathrm{sims})|\theta_\mathrm{sims}) + \blue{\lambda p_\mathrm{sims}(S(x_\mathrm{obs}))}
S:
Summariser (neural net)
(\theta_\mathrm{sims}, x_\mathrm{sims})
x_\mathrm{obs}
\mathcal{L} = I(S(x_\mathrm{sims})|\theta_\mathrm{sims})
Increase the evidence of the observations
Sims misspecified
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By carol cuesta
