TY  - GEN
AV  - public
A1  - Casas Castro, Santiago
N2  - In this thesis we investigate the importance of non-linear structure formation on the
determination of cosmological parameters for models beyond the standard ?CDM
scenario. Future galaxy surveys will be able to determine the two-point correlation
function of more than 10^7 galaxies in a very precise way. Extracting the information encoded in this function at small scales, allows us to constrain the underlying
cosmological model. Here we consider different models beyond ?CDM: Coupled
Dark Energy, Growing Neutrino Quintessence, Effective Field Theory, Horndeski
theory and general phenomenological parameterizations of Modified Gravity. To
study the non-linear effects in these models, we use different methodologies: fitting formulae, semi-analytic prescriptions based on the Halo model, resummation
methods in cosmological perturbation theory and specialized N-body simulations.
In order to forecast the constraining power of next-generation surveys, such as Euclid, SKA and DESI, we developed a code that uses the Bayesian Fisher matrix for-
malism to compute the inferred error on the parameters for Galaxy Clustering and
Weak Lensing observables. For Modified Gravity we study the effect that different
parameterizations and different non-linear prescriptions have on the Fisher forecasts. We obtain the best combination of redshift-binned parameters which will
be measured by future experiments. Within the Coupled Dark Energy scenario
we perform the first forecasts using fitting formulae from N-body simulations and
show that using non-linear scales improves the constraints by more than an order
of magnitude compared to linear forecasts. In the Growing Neutrino Quintessence
model, we use non-Newtonian N-body simulations to study the different regimes
for the dynamics of neutrino lumps. We show that there are viable cosmologies
within this model and that the lump interactions induce a heating of the neutrino
fluid. Finally, we also study analytically the non-linear corrections to the power
spectrum in the case of Horndeski theory under the quasistatic approximation. To
achieve this, we apply a resummation method for higher order perturbation theory,
which had so far only been employed within the standard cosmological model. The
main message of this thesis is that non-linear structure formation has a significant
impact on cosmological parameter estimation. In order to discriminate between
competing theories, using forthcoming data, we need to take non-linearities and
their implications into account.
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/23120/
ID  - heidok23120
TI  - Non-linear structure formation in models of Dark Energy and Modified Gravity
Y1  - 2017///
ER  -