Post on 29-May-2018
Investigating Dark Energy and Gravitation at
cosmological scales with EUCLID
Alain Blanchard
LaThuile, March 26th, 2015
Alain Blanchard Investigating dark gravity with EUCLID
Λ CDM modelremarkable success
Successes of Λ CDM model
Alain Blanchard Investigating dark gravity with EUCLID
Λ CDM modelremarkable success
Successes of Λ CDM model
SnIa
Alain Blanchard Investigating dark gravity with EUCLID
Λ CDM modelremarkable success
Successes of Λ CDM model
SnIa
BAO
Alain Blanchard Investigating dark gravity with EUCLID
Λ CDM modelremarkable success
Successes of Λ CDM model
SnIa
BAO
CMB
Alain Blanchard Investigating dark gravity with EUCLID
Precision cosmology area
Alain Blanchard Investigating dark gravity with EUCLID
Precision cosmology area
Alain Blanchard Investigating dark gravity with EUCLID
Precision cosmology area
Alain Blanchard Investigating dark gravity with EUCLID
Precision cosmology area
Alain Blanchard Investigating dark gravity with EUCLID
Tightening down Dark Energy properties
Tools
Alain Blanchard Investigating dark gravity with EUCLID
Tightening down Dark Energy properties
Tools
Laboratory experiments.
Alain Blanchard Investigating dark gravity with EUCLID
Tightening down Dark Energy properties
Tools
Laboratory experiments. limited
Alain Blanchard Investigating dark gravity with EUCLID
Tightening down Dark Energy properties
Tools
Laboratory experiments. limited
Solar system test.
Alain Blanchard Investigating dark gravity with EUCLID
Tightening down Dark Energy properties
Tools
Laboratory experiments. limited
Solar system test. ...
Alain Blanchard Investigating dark gravity with EUCLID
Tightening down Dark Energy properties
Tools
Laboratory experiments. limited
Solar system test. ...
Galactic level.
Alain Blanchard Investigating dark gravity with EUCLID
Tightening down Dark Energy properties
Tools
Laboratory experiments. limited
Solar system test. ...
Galactic level. NL ...
Alain Blanchard Investigating dark gravity with EUCLID
Tightening down Dark Energy properties
Tools
Laboratory experiments. limited
Solar system test. ...
Galactic level. NL ...
Cosmological scales:
Alain Blanchard Investigating dark gravity with EUCLID
Tightening down Dark Energy properties
Tools
Laboratory experiments. limited
Solar system test. ...
Galactic level. NL ...
Cosmological scales:Let’s go for it!
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID: bureaucracy...
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID
Goals
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID
Goals
Provide astrophysical data (z ≤∼ 2) for investigating Dark Energy:
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID
Goals
Provide astrophysical data (z ≤∼ 2) for investigating Dark Energy:
Weak lensing.
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID
Goals
Provide astrophysical data (z ≤∼ 2) for investigating Dark Energy:
Weak lensing.
Galaxy clustering & Redshift distorsion.
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID
Goals
Provide astrophysical data (z ≤∼ 2) for investigating Dark Energy:
Weak lensing.
Galaxy clustering & Redshift distorsion.
Secondary probes
Clusters.
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID
Goals
Provide astrophysical data (z ≤∼ 2) for investigating Dark Energy:
Weak lensing.
Galaxy clustering & Redshift distorsion.
Secondary probes
Clusters.
CBM/X cross correlations.
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID
Goals
Provide astrophysical data (z ≤∼ 2) for investigating Dark Energy:
Weak lensing.
Galaxy clustering & Redshift distorsion.
Secondary probes
Clusters.
CBM/X cross correlations.
Strong lensing.
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID
Goals
Provide astrophysical data (z ≤∼ 2) for investigating Dark Energy:
Weak lensing.
Galaxy clustering & Redshift distorsion.
Secondary probes
Clusters.
CBM/X cross correlations.
Strong lensing.
Legacy Science
Primeval Universe.
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID
Goals
Provide astrophysical data (z ≤∼ 2) for investigating Dark Energy:
Weak lensing.
Galaxy clustering & Redshift distorsion.
Secondary probes
Clusters.
CBM/X cross correlations.
Strong lensing.
Legacy Science
Primeval Universe.
Galaxy/AGN evolution.
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID
Goals
Provide astrophysical data (z ≤∼ 2) for investigating Dark Energy:
Weak lensing.
Galaxy clustering & Redshift distorsion.
Secondary probes
Clusters.
CBM/X cross correlations.
Strong lensing.
Legacy Science
Primeval Universe.
Galaxy/AGN evolution.
Local Universe
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID
Goals
Provide astrophysical data (z ≤∼ 2) for investigating Dark Energy:
Weak lensing.
Galaxy clustering & Redshift distorsion.
Secondary probes
Clusters.
CBM/X cross correlations.
Strong lensing.
Legacy Science
Primeval Universe.
Galaxy/AGN evolution.
Local Universe
Milky Way,
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID
Goals
Provide astrophysical data (z ≤∼ 2) for investigating Dark Energy:
Weak lensing.
Galaxy clustering & Redshift distorsion.
Secondary probes
Clusters.
CBM/X cross correlations.
Strong lensing.
Legacy Science
Primeval Universe.
Galaxy/AGN evolution.
Local Universe
Milky Way, Exo-Planets,
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID
Goals
Provide astrophysical data (z ≤∼ 2) for investigating Dark Energy:
Weak lensing.
Galaxy clustering & Redshift distorsion.
Secondary probes
Clusters.
CBM/X cross correlations.
Strong lensing.
Legacy Science
Primeval Universe.
Galaxy/AGN evolution.
Local Universe
Milky Way, Exo-Planets, SNe & Transients
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID: Science Working Groups (SWG)
Weak lensing (H.Hoekstra, T.Kitching, K.Benabed).
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID: Science Working Groups (SWG)
Weak lensing (H.Hoekstra, T.Kitching, K.Benabed).
Galaxy clustering (L.Guzzo, W.Percival, Y.Wang).
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID: Science Working Groups (SWG)
Weak lensing (H.Hoekstra, T.Kitching, K.Benabed).
Galaxy clustering (L.Guzzo, W.Percival, Y.Wang).
Clusters (L.Moscardini, J.Weller, J.Bartlett).
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID: Science Working Groups (SWG)
Weak lensing (H.Hoekstra, T.Kitching, K.Benabed).
Galaxy clustering (L.Guzzo, W.Percival, Y.Wang).
Clusters (L.Moscardini, J.Weller, J.Bartlett).
CBM/X cross correlations (N.Ahanim, C.Baccigaluppi.
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID: Science Working Groups (SWG)
Weak lensing (H.Hoekstra, T.Kitching, K.Benabed).
Galaxy clustering (L.Guzzo, W.Percival, Y.Wang).
Clusters (L.Moscardini, J.Weller, J.Bartlett).
CBM/X cross correlations (N.Ahanim, C.Baccigaluppi.
Strong lensing (M.Meneghetti, J.-P. Kneib, R. Gavazzi).
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID: Science Working Groups (SWG)
Weak lensing (H.Hoekstra, T.Kitching, K.Benabed).
Galaxy clustering (L.Guzzo, W.Percival, Y.Wang).
Clusters (L.Moscardini, J.Weller, J.Bartlett).
CBM/X cross correlations (N.Ahanim, C.Baccigaluppi.
Strong lensing (M.Meneghetti, J.-P. Kneib, R. Gavazzi).
Theory (L.Amendola, M.Kunz, M.Viel).
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID: Science Working Groups (SWG)
Weak lensing (H.Hoekstra, T.Kitching, K.Benabed).
Galaxy clustering (L.Guzzo, W.Percival, Y.Wang).
Clusters (L.Moscardini, J.Weller, J.Bartlett).
CBM/X cross correlations (N.Ahanim, C.Baccigaluppi.
Strong lensing (M.Meneghetti, J.-P. Kneib, R. Gavazzi).
Theory (L.Amendola, M.Kunz, M.Viel).
Cosmological simulations (P.Fosalba, R.Teyssier).
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID: Science Working Groups (SWG)
Weak lensing (H.Hoekstra, T.Kitching, K.Benabed).
Galaxy clustering (L.Guzzo, W.Percival, Y.Wang).
Clusters (L.Moscardini, J.Weller, J.Bartlett).
CBM/X cross correlations (N.Ahanim, C.Baccigaluppi.
Strong lensing (M.Meneghetti, J.-P. Kneib, R. Gavazzi).
Theory (L.Amendola, M.Kunz, M.Viel).
Cosmological simulations (P.Fosalba, R.Teyssier).
Primeval Universe (J.-G. Cuby, J Fynbo).
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID: Science Working Groups (SWG)
Weak lensing (H.Hoekstra, T.Kitching, K.Benabed).
Galaxy clustering (L.Guzzo, W.Percival, Y.Wang).
Clusters (L.Moscardini, J.Weller, J.Bartlett).
CBM/X cross correlations (N.Ahanim, C.Baccigaluppi.
Strong lensing (M.Meneghetti, J.-P. Kneib, R. Gavazzi).
Theory (L.Amendola, M.Kunz, M.Viel).
Cosmological simulations (P.Fosalba, R.Teyssier).
Primeval Universe (J.-G. Cuby, J Fynbo).
Galaxy/AGN evolution (J.Brichmann, D.Elbaz, A.Cimati).
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID: Science Working Groups (SWG)
Weak lensing (H.Hoekstra, T.Kitching, K.Benabed).
Galaxy clustering (L.Guzzo, W.Percival, Y.Wang).
Clusters (L.Moscardini, J.Weller, J.Bartlett).
CBM/X cross correlations (N.Ahanim, C.Baccigaluppi.
Strong lensing (M.Meneghetti, J.-P. Kneib, R. Gavazzi).
Theory (L.Amendola, M.Kunz, M.Viel).
Cosmological simulations (P.Fosalba, R.Teyssier).
Primeval Universe (J.-G. Cuby, J Fynbo).
Galaxy/AGN evolution (J.Brichmann, D.Elbaz, A.Cimati).
Local Universe (B.Poggianti, C. Conselice)
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID: Science Working Groups (SWG)
Weak lensing (H.Hoekstra, T.Kitching, K.Benabed).
Galaxy clustering (L.Guzzo, W.Percival, Y.Wang).
Clusters (L.Moscardini, J.Weller, J.Bartlett).
CBM/X cross correlations (N.Ahanim, C.Baccigaluppi.
Strong lensing (M.Meneghetti, J.-P. Kneib, R. Gavazzi).
Theory (L.Amendola, M.Kunz, M.Viel).
Cosmological simulations (P.Fosalba, R.Teyssier).
Primeval Universe (J.-G. Cuby, J Fynbo).
Galaxy/AGN evolution (J.Brichmann, D.Elbaz, A.Cimati).
Local Universe (B.Poggianti, C. Conselice)
Milky Way (E.Tolstoy, A. Ferguson)
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID: Science Working Groups (SWG)
Weak lensing (H.Hoekstra, T.Kitching, K.Benabed).
Galaxy clustering (L.Guzzo, W.Percival, Y.Wang).
Clusters (L.Moscardini, J.Weller, J.Bartlett).
CBM/X cross correlations (N.Ahanim, C.Baccigaluppi.
Strong lensing (M.Meneghetti, J.-P. Kneib, R. Gavazzi).
Theory (L.Amendola, M.Kunz, M.Viel).
Cosmological simulations (P.Fosalba, R.Teyssier).
Primeval Universe (J.-G. Cuby, J Fynbo).
Galaxy/AGN evolution (J.Brichmann, D.Elbaz, A.Cimati).
Local Universe (B.Poggianti, C. Conselice)
Milky Way (E.Tolstoy, A. Ferguson)
Exo-Planets (J.-P. Beaulieu, M. Zapatero-Osorio, E.Kerins)
Alain Blanchard Investigating dark gravity with EUCLID
Basics of EUCLID: Science Working Groups (SWG)
Weak lensing (H.Hoekstra, T.Kitching, K.Benabed).
Galaxy clustering (L.Guzzo, W.Percival, Y.Wang).
Clusters (L.Moscardini, J.Weller, J.Bartlett).
CBM/X cross correlations (N.Ahanim, C.Baccigaluppi.
Strong lensing (M.Meneghetti, J.-P. Kneib, R. Gavazzi).
Theory (L.Amendola, M.Kunz, M.Viel).
Cosmological simulations (P.Fosalba, R.Teyssier).
Primeval Universe (J.-G. Cuby, J Fynbo).
Galaxy/AGN evolution (J.Brichmann, D.Elbaz, A.Cimati).
Local Universe (B.Poggianti, C. Conselice)
Milky Way (E.Tolstoy, A. Ferguson)
Exo-Planets (J.-P. Beaulieu, M. Zapatero-Osorio, E.Kerins)
SNe & Transients (I.Hook, C.Tao, E.Cappellaro).
Alain Blanchard Investigating dark gravity with EUCLID
Astrophysical point of view
Testing cosmology at the background level
Alain Blanchard Investigating dark gravity with EUCLID
Astrophysical point of view
Testing cosmology at the background level
D(z) =1.
H0Ω1/2K
SK
(
H0Ω1/2K
∫ z
0
dz
H(z)
)
Alain Blanchard Investigating dark gravity with EUCLID
Astrophysical point of view
Testing cosmology at the background level
D(z) =1.
H0Ω1/2K
SK
(
H0Ω1/2K
∫ z
0
dz
H(z)
)
SNIa, CMB, tranversal BAO
Alain Blanchard Investigating dark gravity with EUCLID
Astrophysical point of view
Testing cosmology at the background level
D(z) =1.
H0Ω1/2K
SK
(
H0Ω1/2K
∫ z
0
dz
H(z)
)
SNIa, CMB, tranversal BAO
H(z)
Alain Blanchard Investigating dark gravity with EUCLID
Astrophysical point of view
Testing cosmology at the background level
D(z) =1.
H0Ω1/2K
SK
(
H0Ω1/2K
∫ z
0
dz
H(z)
)
SNIa, CMB, tranversal BAO
H(z)longitudinal BAO, z , t(z)
Alain Blanchard Investigating dark gravity with EUCLID
Astrophysical point of view
Testing cosmology at the background level
D(z) =1.
H0Ω1/2K
SK
(
H0Ω1/2K
∫ z
0
dz
H(z)
)
SNIa, CMB, tranversal BAO
H(z)longitudinal BAO, z , t(z)
Testing cosmology at the (linear) perturbation level
Alain Blanchard Investigating dark gravity with EUCLID
Astrophysical point of view
Testing cosmology at the background level
D(z) =1.
H0Ω1/2K
SK
(
H0Ω1/2K
∫ z
0
dz
H(z)
)
SNIa, CMB, tranversal BAO
H(z)longitudinal BAO, z , t(z)
Testing cosmology at the (linear) perturbation level
G (z)δ(z) = G (z)δ0 growth factor
Alain Blanchard Investigating dark gravity with EUCLID
Astrophysical point of view
Testing cosmology at the background level
D(z) =1.
H0Ω1/2K
SK
(
H0Ω1/2K
∫ z
0
dz
H(z)
)
SNIa, CMB, tranversal BAO
H(z)longitudinal BAO, z , t(z)
Testing cosmology at the (linear) perturbation level
G (z)δ(z) = G (z)δ0 growth factordln(G)dln(a) ∼ Ωγ
m(a)
Alain Blanchard Investigating dark gravity with EUCLID
Astrophysical point of view
Testing cosmology at the background level
D(z) =1.
H0Ω1/2K
SK
(
H0Ω1/2K
∫ z
0
dz
H(z)
)
SNIa, CMB, tranversal BAO
H(z)longitudinal BAO, z , t(z)
Testing cosmology at the (linear) perturbation level
G (z)δ(z) = G (z)δ0 growth factordln(G)dln(a) ∼ Ωγ
m(a)
γ is the growth index (γ ∼ 0.55 in ΛCDM)
Alain Blanchard Investigating dark gravity with EUCLID
Astrophysical point of view
Testing cosmology at the background level
D(z) =1.
H0Ω1/2K
SK
(
H0Ω1/2K
∫ z
0
dz
H(z)
)
SNIa, CMB, tranversal BAO
H(z)longitudinal BAO, z , t(z)
Testing cosmology at the (linear) perturbation level
G (z)δ(z) = G (z)δ0 growth factordln(G)dln(a) ∼ Ωγ
m(a)
γ is the growth index (γ ∼ 0.55 in ΛCDM)Weak Lensing,
Alain Blanchard Investigating dark gravity with EUCLID
Astrophysical point of view
Testing cosmology at the background level
D(z) =1.
H0Ω1/2K
SK
(
H0Ω1/2K
∫ z
0
dz
H(z)
)
SNIa, CMB, tranversal BAO
H(z)longitudinal BAO, z , t(z)
Testing cosmology at the (linear) perturbation level
G (z)δ(z) = G (z)δ0 growth factordln(G)dln(a) ∼ Ωγ
m(a)
γ is the growth index (γ ∼ 0.55 in ΛCDM)Weak Lensing, RSD, Clusters
Alain Blanchard Investigating dark gravity with EUCLID
Fiducial model of dark energy
Quintessence : scalar field with minimal couplings and canonicalkinetic energy.
Alain Blanchard Investigating dark gravity with EUCLID
Fiducial model of dark energy
Quintessence : scalar field with minimal couplings and canonicalkinetic energy.
S =
∫
d4x√
g
[
R
16πG− 1
2gµνgµν∂µφ∂νφ− V (φ) + Lm
]
Alain Blanchard Investigating dark gravity with EUCLID
Fiducial model of dark energy
Quintessence : scalar field with minimal couplings and canonicalkinetic energy.
S =
∫
d4x√
g
[
R
16πG− 1
2gµνgµν∂µφ∂νφ− V (φ) + Lm
]
Equation of state parameter:
w =P
ρ=
1/2φ2 − V (φ)
1/2φ2 + V (φ)
Alain Blanchard Investigating dark gravity with EUCLID
Fiducial model of dark energy
Quintessence : scalar field with minimal couplings and canonicalkinetic energy.
S =
∫
d4x√
g
[
R
16πG− 1
2gµνgµν∂µφ∂νφ− V (φ) + Lm
]
Equation of state parameter:
w =P
ρ=
1/2φ2 − V (φ)
1/2φ2 + V (φ)
CPL parametrization: w(z) = wp + (1 − a)wa
Alain Blanchard Investigating dark gravity with EUCLID
Fiducial model of dark energy
Quintessence : scalar field with minimal couplings and canonicalkinetic energy.
S =
∫
d4x√
g
[
R
16πG− 1
2gµνgµν∂µφ∂νφ− V (φ) + Lm
]
Equation of state parameter:
w =P
ρ=
1/2φ2 − V (φ)
1/2φ2 + V (φ)
CPL parametrization: w(z) = wp + (1 − a)wa
growth index:
γ = 0.55 + 0.05[1 + w(z = 1)](fitted)
Alain Blanchard Investigating dark gravity with EUCLID
Fiducial model of dark energy
Quintessence : scalar field with minimal couplings and canonicalkinetic energy.
S =
∫
d4x√
g
[
R
16πG− 1
2gµνgµν∂µφ∂νφ− V (φ) + Lm
]
Equation of state parameter:
w =P
ρ=
1/2φ2 − V (φ)
1/2φ2 + V (φ)
CPL parametrization: w(z) = wp + (1 − a)wa
growth index:
γ = 0.55 + 0.05[1 + w(z = 1)](fitted)
Quintessence has γ ∼ 0.55 “ standard dark energy model”
Alain Blanchard Investigating dark gravity with EUCLID
Astrophysical point of view
Alain Blanchard Investigating dark gravity with EUCLID
Where we go:
Alain Blanchard Investigating dark gravity with EUCLID
Where we go:
Alain Blanchard Investigating dark gravity with EUCLID
Where we go:
R ∝ −(ρ+ 3P)R
Alain Blanchard Investigating dark gravity with EUCLID
The Curvature–Newtonian Potential diagram.
Psaltis 2008.
Alain Blanchard Investigating dark gravity with EUCLID
Further reading
Euclid Definition Study Report mission
R. Laureijs et al., Euclid red book : arXiv:1110.3193
Alain Blanchard Investigating dark gravity with EUCLID
Further reading
Euclid Definition Study Report mission
R. Laureijs et al., Euclid red book : arXiv:1110.3193
Cosmology and fundamental physics with the Euclid satellite.
L. Amendola et al., Living Reviews in Relativity 16, 6 (2013).
Alain Blanchard Investigating dark gravity with EUCLID
Perturbation dynamics
Scalar Perturbations (Newtonnian gauge)
ds2 = a2(t)[−(1 + 2Ψ)dt2 + (1 − 2Φ)dx idxi ]
Alain Blanchard Investigating dark gravity with EUCLID
Perturbation dynamics
Scalar Perturbations (Newtonnian gauge)
ds2 = a2(t)[−(1 + 2Ψ)dt2 + (1 − 2Φ)dx idxi ]
Sub-horizon dynamics
−k2Φ = 4πGQ(a, k)a2ρm∆m
Alain Blanchard Investigating dark gravity with EUCLID
Perturbation dynamics
Scalar Perturbations (Newtonnian gauge)
ds2 = a2(t)[−(1 + 2Ψ)dt2 + (1 − 2Φ)dx idxi ]
Sub-horizon dynamics
−k2Φ = 4πGQ(a, k)a2ρm∆m
Ψ− Φ relation:Φ = η(a, k)Ψ
Alain Blanchard Investigating dark gravity with EUCLID
Perturbation dynamics
Scalar Perturbations (Newtonnian gauge)
ds2 = a2(t)[−(1 + 2Ψ)dt2 + (1 − 2Φ)dx idxi ]
Sub-horizon dynamics
−k2Φ = 4πGQ(a, k)a2ρm∆m
Ψ− Φ relation:Φ = η(a, k)Ψ
For a given DE/MG theory, Q, η can be computed and equationsfor perturbations can be solved.
Alain Blanchard Investigating dark gravity with EUCLID
From redshift survey
Alain Blanchard Investigating dark gravity with EUCLID
From redshift survey
Pg (k)
Alain Blanchard Investigating dark gravity with EUCLID
From redshift survey
Pg (k) then to PDM(k)
Alain Blanchard Investigating dark gravity with EUCLID
From redshift survey
Alain Blanchard Investigating dark gravity with EUCLID
From redshift survey
Access to ΦAlain Blanchard Investigating dark gravity with EUCLID
From weak lensing
Alain Blanchard Investigating dark gravity with EUCLID
From weak lensing
Dark matter tomography
Alain Blanchard Investigating dark gravity with EUCLID
From weak lensing
Alain Blanchard Investigating dark gravity with EUCLID
From weak lensing
Access to ψ +Φ
Alain Blanchard Investigating dark gravity with EUCLID
Models of dark energy and modified gravity
Alain Blanchard Investigating dark gravity with EUCLID
Models of dark energy and modified gravity
Beyond standard DE model
Alain Blanchard Investigating dark gravity with EUCLID
Models of dark energy and modified gravity
Beyond standard DE model: differences between DE and MG is lessclear: a modification to Einstein’s equation can be interpreted asstandard Einstein gravity with a modified “matter” source (⊃scalars, vectors and tensors).
Alain Blanchard Investigating dark gravity with EUCLID
Models of dark energy and modified gravity
Beyond standard DE model: differences between DE and MG is lessclear: a modification to Einstein’s equation can be interpreted asstandard Einstein gravity with a modified “matter” source (⊃scalars, vectors and tensors).
Terminology :
Alain Blanchard Investigating dark gravity with EUCLID
Models of dark energy and modified gravity
Beyond standard DE model: differences between DE and MG is lessclear: a modification to Einstein’s equation can be interpreted asstandard Einstein gravity with a modified “matter” source (⊃scalars, vectors and tensors).
Terminology :
Standard dark energy: standard gravity, canonical kineticenergy, minimal couplings, sound speed = c.
Alain Blanchard Investigating dark gravity with EUCLID
Models of dark energy and modified gravity
Beyond standard DE model: differences between DE and MG is lessclear: a modification to Einstein’s equation can be interpreted asstandard Einstein gravity with a modified “matter” source (⊃scalars, vectors and tensors).
Terminology :
Standard dark energy: standard gravity, canonical kineticenergy, minimal couplings, sound speed = c.
Clustering dark energy: k-essence
Alain Blanchard Investigating dark gravity with EUCLID
Models of dark energy and modified gravity
Beyond standard DE model: differences between DE and MG is lessclear: a modification to Einstein’s equation can be interpreted asstandard Einstein gravity with a modified “matter” source (⊃scalars, vectors and tensors).
Terminology :
Standard dark energy: standard gravity, canonical kineticenergy, minimal couplings, sound speed = c.
Clustering dark energy: k-essence
Explicit modified gravity models: F (R), Scalar-tensor theories(F (φ)R), Gauss-Bonnet...
Alain Blanchard Investigating dark gravity with EUCLID
Models of dark energy and modified gravity
Coupled dark energy models
Alain Blanchard Investigating dark gravity with EUCLID
Models of dark energy and modified gravity
Coupled dark energy models
S =
∫
d4x√
g
[
R
16πG− 1
2gµνgµν∂µφ∂νφ− V (φ) + m(φ)ψψ + Lm(ψ)
]
Alain Blanchard Investigating dark gravity with EUCLID
Models of dark energy and modified gravity
Coupled dark energy models
S =
∫
d4x√
g
[
R
16πG− 1
2gµνgµν∂µφ∂νφ− V (φ) + m(φ)ψψ + Lm(ψ)
]
coupling can be with baryons, neutrinos, dark matter...
Alain Blanchard Investigating dark gravity with EUCLID
Models of dark energy and modified gravity
Coupled dark energy models
S =
∫
d4x√
g
[
R
16πG− 1
2gµνgµν∂µφ∂νφ− V (φ) + m(φ)ψψ + Lm(ψ)
]
coupling can be with baryons, neutrinos, dark matter...writing m(φ) = m exp(−β(φ)φ) then :
G = G (1 + 2β2(φ)
Alain Blanchard Investigating dark gravity with EUCLID
Models of dark energy and modified gravity
Classifying theories:
Alain Blanchard Investigating dark gravity with EUCLID
Models of dark energy and modified gravity
Classifying theories:
Identify a limited number of parameters that can be determinedfrom observations and which are meaningful in the “space oftheories”
Alain Blanchard Investigating dark gravity with EUCLID
Models of dark energy and modified gravity
Classifying theories:
Identify a limited number of parameters that can be determinedfrom observations and which are meaningful in the “space oftheories”
Parametrized Post Friedmann (PPF) formalism
Alain Blanchard Investigating dark gravity with EUCLID
Models of dark energy and modified gravity
Classifying theories:
Identify a limited number of parameters that can be determinedfrom observations and which are meaningful in the “space oftheories”
Parametrized Post Friedmann (PPF) formalism
Effective Field Theories (EFT)
Alain Blanchard Investigating dark gravity with EUCLID
Models of dark energy and modified gravity
Classifying theories:
Identify a limited number of parameters that can be determinedfrom observations and which are meaningful in the “space oftheories”
Parametrized Post Friedmann (PPF) formalism
Effective Field Theories (EFT)
...
Alain Blanchard Investigating dark gravity with EUCLID
One more comment...Friedmann-Lemaître equation:
(
R
R
)2
=8πGρm
3+
8πGρDE
3− kc2
R2
Alain Blanchard Investigating dark gravity with EUCLID
One more comment...Friedmann-Lemaître equation:
(
R
R
)2
=8πGρm
3+
8πGρDE
3− kc2
R2
The split between ρm and ρDE is not (gravitationally) testable(Kunz 2009)
Alain Blanchard Investigating dark gravity with EUCLID
One more comment...Friedmann-Lemaître equation:
(
R
R
)2
=8πGρm
3+
8πGρDE
3− kc2
R2
The split between ρm and ρDE is not (gravitationally) testable(Kunz 2009)Just use it as a parametrization.
Alain Blanchard Investigating dark gravity with EUCLID
Precision cosmology area: curvature
Alain Blanchard Investigating dark gravity with EUCLID
A Cosmological Test of GR at the background levelDynamic
One can derive dynamical equation for a(t) from Newtonianconsideration
Alain Blanchard Investigating dark gravity with EUCLID
A Cosmological Test of GR at the background levelDynamic
One can derive dynamical equation for a(t) from Newtonianconsideration
Newtonian dynamic:
a2 + K =8πG
3
∑
ρa2.
(see Mukhanov’s book)
Alain Blanchard Investigating dark gravity with EUCLID
A Cosmological Test of GR at the background levelDynamic
One can derive dynamical equation for a(t) from Newtonianconsideration
Newtonian dynamic:
a2 + K =8πG
3
∑
ρa2.
(see Mukhanov’s book)
General Relativity
K = c2
soΩk = 1.−
∑
Ωcontents
Alain Blanchard Investigating dark gravity with EUCLID
Testing GR at cosmological scales
Alain Blanchard Investigating dark gravity with EUCLID
Testing GR at cosmological scales
so testing:
Ωk = 1.−∑
Ωcontents
is testing GR on large scale at the background level
Alain Blanchard Investigating dark gravity with EUCLID
Testing GR at cosmological scales
so testing:
Ωk = 1.−∑
Ωcontents
is testing GR on large scale at the background level
So we can define :
Ωkgeo = − k
(a0H0)2
andΩkdyn = 1.−
∑
Ωcontents
Alain Blanchard Investigating dark gravity with EUCLID
Testing GR at cosmological scales
so testing:
Ωk = 1.−∑
Ωcontents
is testing GR on large scale at the background level
So we can define :
Ωkgeo = − k
(a0H0)2
andΩkdyn = 1.−
∑
Ωcontents
and use SNIa, CMB, BAO to constrain these quantities.Yves Zolnierowski & AB, arXiv:1503.00111
Alain Blanchard Investigating dark gravity with EUCLID
With w = −1
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
-0.1 -0.08 -0.06 -0.04 -0.02 0 0.02 0.04
Ωkgeo
Ωk d
yn
Alain Blanchard Investigating dark gravity with EUCLID
With w free
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
-0.1 -0.08 -0.06 -0.04 -0.02 0 0.02 0.04Ωkgeo
Ωk d
yn
Alain Blanchard Investigating dark gravity with EUCLID
With w free
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
-2.5 -2 -1.5 -1 -0.5 0 0.5
Ωk d
yn
w
Alain Blanchard Investigating dark gravity with EUCLID
Conclusion
Euclid will allow to test gravity at
cosmological scale in many ways
Alain Blanchard Investigating dark gravity with EUCLID
Conclusion
Euclid will allow to test gravity at
cosmological scale in many ways
This can/should be complemented by
other data from cosmological relevance
(CMB, H0, z , t(z), ...)
Alain Blanchard Investigating dark gravity with EUCLID
Conclusion
Euclid will allow to test gravity at
cosmological scale in many ways
This can/should be complemented by
other data from cosmological relevance
(CMB, H0, z , t(z), ...)
First results at Moriond 2021 (TBC)
Alain Blanchard Investigating dark gravity with EUCLID
Conclusion
Euclid will allow to test gravity at
cosmological scale in many ways
This can/should be complemented by
other data from cosmological relevance
(CMB, H0, z , t(z), ...)
First results at Moriond 2021 (TBC)
Thank You
Alain Blanchard Investigating dark gravity with EUCLID