TY - JOUR
T1 - Euclid preparation
T2 - XV. Forecasting cosmological constraints for the $Euclid$ and CMB joint analysis
AU - Euclid Collaboration
AU - Ilić, S.
AU - Aghanim, N.
AU - Baccigalupi, C.
AU - Bermejo-Climent, J. R.
AU - Fabbian, G.
AU - Legrand, L.
AU - Paoletti, D.
AU - Branchini, E.
AU - Taylor, A. N.
AU - Valentijn, E. A.
AU - Verdoes Kleijn, G. A.
PY - 2022/1/1
Y1 - 2022/1/1
N2 - The combination and cross-correlation of the upcoming Euclid data with
cosmic microwave background (CMB) measurements is a source of great
expectation since it will provide the largest lever arm of epochs,
ranging from recombination to structure formation across the entire past
light cone. In this work, we present forecasts for the joint analysis of
Euclid and CMB data on the cosmological parameters of the standard
cosmological model and some of its extensions. This work expands and
complements the recently published forecasts based on Euclid-specific
probes, namely galaxy clustering, weak lensing, and their
cross-correlation. With some assumptions on the specifications of
current and future CMB experiments, the predicted constraints are
obtained from both a standard Fisher formalism and a posterior-fitting
approach based on actual CMB data. Compared to a Euclid-only analysis,
the addition of CMB data leads to a substantial impact on constraints
for all cosmological parameters of the standard
Λ-cold-dark-matter model, with improvements reaching up to a
factor of ten. For the parameters of extended models, which include a
redshift-dependent dark energy equation of state, non-zero curvature,
and a phenomenological modification of gravity, improvements can be of
the order of two to three, reaching higher than ten in some cases. The
results highlight the crucial importance for cosmological constraints of
the combination and cross-correlation of Euclid probes with CMB data.
AB - The combination and cross-correlation of the upcoming Euclid data with
cosmic microwave background (CMB) measurements is a source of great
expectation since it will provide the largest lever arm of epochs,
ranging from recombination to structure formation across the entire past
light cone. In this work, we present forecasts for the joint analysis of
Euclid and CMB data on the cosmological parameters of the standard
cosmological model and some of its extensions. This work expands and
complements the recently published forecasts based on Euclid-specific
probes, namely galaxy clustering, weak lensing, and their
cross-correlation. With some assumptions on the specifications of
current and future CMB experiments, the predicted constraints are
obtained from both a standard Fisher formalism and a posterior-fitting
approach based on actual CMB data. Compared to a Euclid-only analysis,
the addition of CMB data leads to a substantial impact on constraints
for all cosmological parameters of the standard
Λ-cold-dark-matter model, with improvements reaching up to a
factor of ten. For the parameters of extended models, which include a
redshift-dependent dark energy equation of state, non-zero curvature,
and a phenomenological modification of gravity, improvements can be of
the order of two to three, reaching higher than ten in some cases. The
results highlight the crucial importance for cosmological constraints of
the combination and cross-correlation of Euclid probes with CMB data.
KW - large-scale structure of Universe
KW - cosmic background radiation
KW - surveys
KW - methods: statistical
U2 - 10.1051/0004-6361/202141556
DO - 10.1051/0004-6361/202141556
M3 - Article
SN - 0004-6361
VL - 657
JO - Astronomy & Astrophysics
JF - Astronomy & Astrophysics
M1 - A91
ER -