Non-linear matter power spectrum modeling in interacting dark energy cosmologies

Abstract

Understanding the behavior of the matter power spectrum on non-linear scales beyond the CDM model is crucial for accurately predicting the large-scale structure (LSS) of the Universe in non-standard cosmologies. In this work, we present an analysis of the non-linear matter power spectrum within the framework of interacting dark energy dark matter cosmologies (IDE). We employ N-body simu lations and theoretical models to investigate the impact of IDEonthese non-linear scales. Beginning with N-body sim ulations characterized by a fixed parameter space delineated by prior observational research, we adeptly fit the simulated spectra with a simple parametric function, achieving accu racy within 5%. Subsequently, we refine a modified halo model tailored to the IDE cosmology, exhibiting exceptional precision in fitting the simulations down to scales of approx imately 1h/Mpc. To assess the model’s robustness, we con duct a forecast analysis for the Euclid survey, employing our refined model. We find that the coupling parameter ξ will be constrained to σ(ξ)= 0.0110. This marks a signifi cant improvementbyanorderofmagnitudecomparedtoany othercurrentobservationaltestsdocumentedintheliterature. These primary findings pave the way for a novel preliminary approach,enablingtheutilizationofIDEmodelsforobserva tional constraints concerning LSS data on non-linear scales.