Santiago Casas
CEA Paris-Saclay, DAp
Cosmic Microwave Background
Planck 2018 CMB Temperature map (Commander) . wiki.cosmos.esa.int/planck-legacy-archive/index.php/CMB_maps
Large Scale Structure
Illustris Simulation: www.nature.com/articles/nature13316
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
We can observe fluctuations in the temperature of the radiation released at recombination ~380.000 years ago
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Concordance Cosmology:
Santiago Casas @ NineHubCR, 17.04.21
O(100) orders of magnitude wrong
(Zeldovich 1967, Weinberg 1989, Martin 2012).
Composed of naturalness and coincidence
sub-problems, among others.
Quantum Gravity?
Santiago Casas @ NineHubCR, 17.04.21
Planck, Clusters and Lensing tension on clustering amplitude σ8
KiDS 1000 Cosmology, arXiv:2010:16416
L.Verde, et al 2019. arXiv:1907.10625
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
BAO
Clustering
RSD
Spec-z
Euclid Collaboration, IST:Forecasts, arXiv: 1910.09273
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Predicting future constraints, based mostly on the power spectrum
Santiago Casas @ NineHubCR, 17.04.21
Credits: Sunayana Bhargava
21cm Intensity Mapping
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Chang et al, Nature 2010
Intensity Mapping line detected in cross-correlation with galaxies
Foregrounds: 125mK
21cm signal: 460 μK
Image credit: Isabella Carucci
Santiago Casas @ NineHubCR, 17.04.21
Current and future experiments covering most of the sky and redshift range
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Image credit: Isabella Carucci
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Image credit: Isabella Carucci
Continuum emission: Allows detection of position and shapes of galaxies.
Line emission of neutral Hydrogen (HI, 21cm):
Using redshifted HI line -> spectroscopic galaxy survey
2. Intensity Mapping: Large scale correlations in HI brightness temperature -> very good redshift resolution,
good probe of structres
Santiago Casas @ NineHubCR, 17.04.21
Image credit: Isabella Carucci
Continuum emission: Allows detection of position and shapes of galaxies.
Line emission of neutral Hydrogen (HI, 21cm):
Using redshifted HI line -> spectroscopic galaxy survey
2. Intensity Mapping: Large scale correlations in HI brightness temperature -> very good redshift resolution,
good probe of structres
Santiago Casas @ NineHubCR, 17.04.21
SKA1 Medium Deep Band 1: 20000deg2
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Ezquiaga, Zumalacárregui, Front. Astron. Space Sci., 2018
Santiago Casas @ NineHubCR, 17.04.21
In ΛCDM the two linear gravitational potentials Ψ and Φ are equal to each other
We can describe general modifications of gravity (of the metric) at the linear level with 2 functions of scale (k) and time (a)
Only two independent functions
Santiago Casas @ NineHubCR, 17.04.21
Planck 2015 results XIV, arXiv:1502.01590
Planck 2018 results VI, arXiv:1807.06209
Casas et al (2017), arXiv:1703.01271
Forecasts for Stage-IV surveys in:
Santiago Casas @ NineHubCR, 17.04.21
Directly constrains MG function Σ through Weyl potential
Santiago Casas @ NineHubCR, 17.04.21
In Casas et al (2016) we studied predictions of these models on the cosmological observables
Santiago Casas @ NineHubCR, 17.04.21
PIM(z,k)=TˉIM(z)2[bIM(z)2+f(z)μ2]2Pδδ,zs(z,k)
bIM(z)=0.3(1+z)+0.6
ΩHI =4(1+z)0.6×10−4
TˉIM(z)=189hH(z)(1+z)2H0ΩHI(z)mK
Jolicoeur et al (2020) arXiv:2009.06197
Carucci et al (2020) arXiv:2006.05996
Santiago Casas @ NineHubCR, 17.04.21
PIM]×GC(z,k)=TˉIM(z)[bIM(z)2+f(z)μ2]×[bg(z)2+f(z)μ2]Pδδ,zs(z,k) ×exp[−21k2μ2(σIM(z)2+σsp(z)2)]rIM,opt
bg(z)= fit to simulations for given galaxy sample
Jolicoeur et al (2020) arXiv:2009.06197
Wolz et al (2021) arXiv:2102.04946
σi(z)=H(z)c(1+z)δz
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Number of dishes
Effective beam
βSD=exp[−8ln2k⊥r(z)2θb(z)2]
αSD =Nd1
Jolicoeur et al (2020) arXiv:2009.06197
Santiago Casas @ NineHubCR, 17.04.21
Santiago Casas @ NineHubCR, 17.04.21
Euclid GCsp
+
SKA1 GCsp (HI galaxies)
PRELIMINARY
Santiago Casas @ NineHubCR, 17.04.21
SKA1:
GCsp (HI galaxies)+IM (HI 21cm)
vs.
GC+WL+XC (Continuum)
PRELIMINARY
Santiago Casas @ NineHubCR, 17.04.21
SKA1:
GCsp (HI galaxies) +
GC+WL+XC (Continuum)
+ IM (HI 21cm)
PRELIMINARY
Santiago Casas @ NineHubCR, 17.04.21
SKA1:
GCsp (HI galaxies) , GC+WL+XC (Continuum), + IM (HI 21cm)
Combined constraints on μ-Σ ~ 3%
PRELIMINARY
Santiago Casas @ NineHubCR, 17.04.21
SKA1:
GC+WL+XC (Continuum) +
IM (HI 21cm) + GCsp(HI)
and Planck'15
PRELIMINARY
Santiago Casas @ NineHubCR, 17.04.21
SKA1:
GC+WL+XC (Continuum) +
IM (HI 21cm) + GCsp(HI)
+ Planck'15
PRELIMINARY
Santiago Casas @ NineHubCR, 17.04.21
PRELIMINARY
SKA1:
GC+WL+XC (Continuum) +
IM (HI 21cm) + GCsp(HI)
Santiago Casas @ NineHubCR, 17.04.21
Text
PRELIMINARY
HI galaxies spectroscopic survey
SKA1 Redbook 2018, arXiv:1811.02743
SKA1 Medium Deep Band 2: 5000deg2
SKA1 Redbook 2018, arXiv:1811.02743
SKA1 Medium Deep Band 2: 5000deg2
Continuum galaxy survey
*kindly provided by Stefano Camera
SKA1 Medium Deep Band 2: 5000deg2
Continuum galaxy survey
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