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Cosmological Simulations Cosmological Simulations Numerical CLONESThe Universe or at least part of it In memory of Cécile Renault You are somewhere therein! Jenny Sorce Centre de Recherche Astrophysique de Lyon Webinar dark energy - May 11th 2021 Motivation : ΛCDM ? Current strategy Observations Simulations ? Directly Cosmological Observable Model Universe Jenny Sorce (CRAL) CLONES 2021 2 Motivation : ΛCDM ? Current strategy Observations Simulations ? Directly Cosmological Observable Model Universe If all goes well… it is a perfect match Jenny Sorce (CRAL) CLONES 2021 3 Motivation : ΛCDM ? In practice Observations Simulations ? Directly Cosmological Observable Model Universe Observations Simulations Springel Overall: ΛCDM Jenny Sorce (CRAL) CLONES 2021 4 Motivation : ΛCDM ? Toward precision cosmology Precision Era: ΛCDM checked on all scales 1-2% precision Observational Dark matter only Duffy 2014 Fosalba2017 Ned Deeper and higher and higher larger surveys resolution simulations Jenny Sorce (CRAL) CLONES 2021 5 Motivation : ΛCDM ? Toward precision cosmology Precision Era: ΛCDM checked on all scales 1-2% precision With baryons Dark matter only Illustris TNG website Fosalba2017 Ned higher and higher resolution simulations Zoom Simulations to retain large scale effects Jenny Sorce (CRAL) CLONES 2021 6 Motivation : ΛCDM ? Toward precision cosmology Precision Era: What is in there? 1-2% precision Thermal Energy shocks AGN tive ➝ B cooling Radia supernova Star formation + Cosmic Rays, etc What more can we do wrt these typical simulations and why ? Jenny Sorce (CRAL) CLONES 2021 7 Motivation : ΛCDM ? with more precision come some tensions ! Let’s start with why Example: Equation of state of the dark energy ΛCDM ObservationCamarena+2018 w= p/ρ tensions hlocal Jenny Sorce (CRAL) CLONES 2021 8 Motivation : ΛCDM ? Precision is not accuracy ! Jenny Sorce (CRAL) CLONES 2021 9 Motivation : ΛCDM ? Precision is not accuracy: environmental biases? Example: Equation of state of the dark energy ΛCDM ObservationCamarena+2018 w= p/ρ tensions hlocal biases due to our environment? Jenny Sorce (CRAL) CLONES 2021 10 Motivation : ΛCDM ? Both precision and accuracy are required! Example: Equation of state of the dark energy ΛCDM Camarena+2018 Without cosmic variance w= p/ρ With cosmic variance hlocal Accuracy: 1% bias non-negligible Jenny Sorce (CRAL) CLONES 2021 11 ΛCDM questioned? Precision cosmology When observations challenge ΛCDM Jenny Sorce (CRAL) CLONES 2021 12 ΛCDM questioned? Precision cosmology A few examples Small scales local scales Large scales local / global H0 CMB Thin disks of satellites North/South Asymmetry >3σ Science Francis+2010 Observed… not simulated very unlikely… Famaey+2013, Bullock+2017 Freedman+2017 e.g. Schwarz+2016 Jenny Sorce (CRAL) CLONES 2021 13 ΛCDM questioned? Precision cosmology A few examples Small scales local scales Large scales local / global H0 CMB Thin disks of satellites North/South Asymmetry >3σ Science Francis+2010 Observed… not simulated very unlikely… Famaey+2013, Bullock+2017 Freedman+2017 e.g. Schwarz+2016 Jenny Sorce (CRAL) CLONES 2021 14 ΛCDM questioned? Precision cosmology A few examples Small scales local scales Large scales local / global H0 CMB Thin disks of satellites North/South Asymmetry >3σ Science Francis+2010 Observed… not simulated very unlikely… Famaey+2013, Bullock+2017 Freedman+2017 e.g. Schwarz+2016 More examples: local void emptier with larger galaxies, CMB/galaxy clusters σ8, lack of angular correlation at large scales local correlations slope and scatter, missing satellites, cold spot, etc Jenny Sorce (CRAL) CLONES 2021 15 Local-induced biases ? Can our local environment bias our ‘’perception’’ at the 1-2% level preventing us from reaching 1-2% accuracy… Small scales Local scales Large scales Are we comparing apple to apple? Are we a neutral observer? What about foreground effects? Do we understand enough? A neutral environment? Photons travel a lot Correlation with environment Very unlikely… before reaching us… and eventually decrease or increase tensions with ΛCDM ? Jenny Sorce (CRAL) CLONES 2021 16 Local-induced biases ? on the small scales Everything relies on the mass estimate of galaxy clusters Planck Dependence on the Pratt+2019 halo mass function estimate Need to understand these physics laboratories before using them as cosmological probes Best known are closeby & Dependence on the environment ! Jenny Sorce (CRAL) CLONES 2021 17 Local-induced biases ? on the local scales A simple example: if we live in a spherical underdensity Hoscheit+2018 Hoscheit+2018 Keenan+2014 ΛCDM + KBC void Observations An example: Hint at a local underdensity up to z=0.07 Jenny Sorce (CRAL) CLONES 2021 18 Local-induced biases ? on the local scales As many effect values as environments Void 1.02 Wojtak+2013 Cluster For an average environment: a 2% bias ! Jenny Sorce (CRAL) CLONES 2021 19 Local-induced biases ? on the large scales Gravitational redshifts and the large scale surveys photons photons Wojtak+2015 Void photons Void 10-3 uncertainty photons photons -0.001 Cluster future large scale surveys Not bound overdensity l As many effect values as environments Wojtak +2015 Void Cluster Wojtak+2015 Value: [10-5 - 10-4] For an average environment: a 1-2% bias ! Jenny Sorce (CRAL) CLONES 2021 20 Local-induced biases ? on the large scales Gravitational redshifts and the large scale surveys photons photons Wojtak+2015 Void photons Void 10-3 uncertainty photons photons -0.001 Cluster future large scale surveys Not bound overdensity l As many effect values as environments Wojtak +2015 Void Cluster Wojtak+2015 Value: [10-5 - 10-4] For an average environment: a 1-2% bias ! Jenny Sorce (CRAL) CLONES 2021 21 Local-induced biases ? on the large scales Gravitational redshifts and the large scale surveys photons photons Wojtak+2015 Void photons Void 10-3 uncertainty photons photons -0.001 Cluster future large scale surveys Not bound overdensity l As many effect values as environments Wojtak +2015 Required Precision ! Void Cluster Wojtak+2015 Value: [10-5 - 10-4] For an average environment: a 1-2% bias ! Jenny Sorce (CRAL) CLONES 2021 22 Local-induced biases ? on the large scales Gravitational redshifts and the large scale surveys photons photons Wojtak+2015 Void photons Void 10-3 uncertainty photons photons -0.001 Cluster future large scale surveys Not bound overdensity l As many effect values as environments Wojtak +2015 Void Cluster Wojtak+2015 Value: [10-5 - 10-4] For an average environment: a 1-2% bias ! Jenny Sorce (CRAL) CLONES 2021 23 Local-induced biases ? on the large scales Gravitational redshifts and the CMB Wojtak+2015 photons Void photons 10-3 uncertainty photons Void Integrated Sachs-Wolfe & Rees-Sciama photons -0.001 Cluster photons Effectsfuture large scale surveys l Not bound overdensity Maturi+2007 As many effect values as environments increasing sensitivity increasing Wojtakprecision WMAP = reducing +2015error bars Planck Void Clusterlocal foreground effect = ‘noise/ Wojtak+2015 bias’ Value: [10-5 - 10-4] For an average environment: a 1-2% bias ! Jenny Sorce (CRAL) CLONES 2021 24 Accounting for the effects crude modeling A crude modeling is a beginning… but not nearly enough… Jenny Sorce (CRAL) CLONES 2021 25 Accounting for the effects crude modeling A few examples Small scales Local scales Large scales H0 local / global local global Average broken North/South asymmetry Science ~2 Underdense Publication year Francis+2010 Do we live in a filament that But correction from redshift reproduces exactly that thin In what kind of density surveys only… plane? do we live exactly? Jenny Sorce (CRAL) CLONES 2021 26 Accounting for the effects crude modeling A few examples Small scales Local scales Large scales H0 local / global local global Average broken North/South asymmetry Science ~2 Underdense Publication year Francis+2010 Do we live in a filament that In what kind of density But correction from redshift reproduces exactly that thin do we live exactly? surveys only… plane? Jenny Sorce (CRAL) CLONES 2021 27 Accounting for the effects crude modeling A few examples Small scales Local scales Large scales H0 local / global local global Average broken North/South asymmetry Science ~2 Underdense Publication year Francis+2010 Do we live in a filament that In what kind of density But correction from redshift reproduces exactly that thin do we live exactly? surveys only… plane? That concludes why we might want to do more Jenny Sorce (CRAL) CLONES 2021 28 Accounting for the effects Summary Let’s continue with what more wrt typical simulations can we do or reformulating how can we build a local modeling in order to account for the local-induced biases? CLONES = Constrained LOcal & Nesting Environment Simulations Jenny Sorce (CRAL) CLONES 2021 29 Local Universe’s initial conditions constrained initial conditions Bayes1761 Wiener1942 Hoffman & Ribak 1991 Zaroubi+1995 van der Weijgaert & Bertshinger 1996 Jenny Sorce (CRAL) CLONES 2021 30 Local Universe’s initial conditions constrained initial conditions Part of the Universe at 13.7 light-Gyr Photons received today have been emitted when it was ~380 000 yrs. old Homogeneous and Isotropic Universe Probability excess to have an object at a distance r from Gaussian white noise w(k) and power spectrum are another = autocorrelation of the density contrast = initial density sufcient to get a … Fourier transform of the power spectrum feld RANDOM realization = whatever part of the Universe Constrained initial Applying local constraints conditions Jenny Sorce (CRAL) CLONES 2021 31 Local Universe’s
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