Computational Cosmology - ics.uzh.chmischak/Research/ResearchPresentation_Mischa.pdf · What does...
Transcript of Computational Cosmology - ics.uzh.chmischak/Research/ResearchPresentation_Mischa.pdf · What does...
Computational Cosmology
Student: Mischa Knabenhans Advisor: Joachim Stadel
How did I get here?
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Elementary School
Fascination for planets & the night sky
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Gymnasium
MATURA THESIS:
The history and development of navigation techniques
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Bachelors:
SEMESTER PROJECTS:
Weak gravitational lensing
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Masters:
SEMESTER PROJECT: Higgs physics
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Master Thesis:
Higher spin black holes in (2+1)-D gravity
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PhD Research:
How does structure form in the Universe?M. Knabenhans 8
MAIN QUESTION:
What is the Universe (like)?
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What is my object of interest?
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What does the Universe look like?
Earth
~12’000 kmM. Knabenhans 11
What does the Universe look like?
~10 000 000 000 km = 1e10 km ~ 0.0003 pcM. Knabenhans 12
What does the Universe look like?
~ 3e14 km ~ 10 pcM. Knabenhans 13
What does the Universe look like?
~ 1e18 km ~ 30 kpcM. Knabenhans 14
What does the Universe look like?
~ 1 MpcM. Knabenhans 15
What does the Universe look like?
~ 30 MpcM. Knabenhans 16
V. Springel et al.
What does the Universe look like?
~ 150 MpcM. Knabenhans 17
What does the Universe look like?
J. Stadel (2017)
~ 1 Gpc ~ 1/10 of observable UniverseM. Knabenhans 18
What does the Universe look like?
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Context & main goal
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EUCLID:
Satellite
Aims at demystifying
DARK ENERGY
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BACKGROUND
Launch in Dec 2020
Maps the geometry of the dark universe out to redshift 2
ESA (sci.esa.int)
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Density fluctuations:
overdense region
underdense region
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LSS Statistics:
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rr
r
r
r
⇠(r) = h�(x)�(x+ r)i
Correlation function
�(x) =⇢(x)� ⇢̄
⇢̄
Density perturbation
Properties of the Universe:
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P (k) = FT [⇠(r)]
Power spectrum
NL Power spectrum - the observable:
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What is my PhD project about?
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TheoryOverview:
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Overview:Theory
Simulation
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Overview:Simulation
Experiment
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Overview:ExperimentSimulation
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Overview:ExperimentSimulation
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Overview:ExperimentSimulation
⌦m,⌦b,⌦⇤, ns, h, w
by comparison
MC: Standard parameter estimation:
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Computational cost:
~15’000 CPU hours
Box size: (1024 Mpc/h)^3 # Particles: 2048^3
A MC approach is infeasible!
⌦m,⌦b,⌦⇤, ns, h, w
Parameter estimation by emulation:
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Computational cost:
~1 CPU second
Box size: (1024 Mpc/h)^3 # Particles: 2048^3
Speed up: 1e6
Emulation can do it!⌦m,⌦b,⌦⇤, ns, h, w
Questions?
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