This work investigates the potential for testing models of gravity with intensity mapping experiments observing the cosmic Dark Ages. Fluctuations in the brightness temperature of the 21 cm line of neutral hydrogen allow to reconstruct the HI distribution and trace the growth of structures across a wide range of scales and redshifts, for the most part yet to be explored. Observations at high redshifts z ∼ 30 − 200, however challenging, present numerous advantages and are in principle a high precision cosmological probe. Indeed, the growth of overdensities is still well described by linear perturbation theory and neutral hydrogen can be considered as an unbiased tracer of the underlying matter distribution, furthermore the signal is free of complications due to hardtomodel astrophysical processes. All of this makes it possible to give an analytical description of the signal and isolate the cosmological information. This thesis aims to generalize existing works on intensity mapping forecasts and develop a formalism and code to compute the angular power spectrum of 21 cm fluctuations during the Dark Ages and constrain the growth of structure. We produce forecasts for the ability of future groundbased radio interferometers, as well as predictions for the proposed radio array on the far side of the Moon, to constrain models of gravity.
This work investigates the potential for testing models of gravity with intensity mapping experiments observing the cosmic Dark Ages. Fluctuations in the brightness temperature of the 21 cm line of neutral hydrogen allow to reconstruct the HI distribution and trace the growth of structures across a wide range of scales and redshifts, for the most part yet to be explored. Observations at high redshifts z ∼ 30 − 200, however challenging, present numerous advantages and are in principle a high precision cosmological probe. Indeed, the growth of overdensities is still well described by linear perturbation theory and neutral hydrogen can be considered as an unbiased tracer of the underlying matter distribution, furthermore the signal is free of complications due to hardtomodel astrophysical processes. All of this makes it possible to give an analytical description of the signal and isolate the cosmological information. This thesis aims to generalize existing works on intensity mapping forecasts and develop a formalism and code to compute the angular power spectrum of 21 cm fluctuations during the Dark Ages and constrain the growth of structure. We produce forecasts for the ability of future groundbased radio interferometers, as well as predictions for the proposed radio array on the far side of the Moon, to constrain models of gravity.
Tests of gravity with intensity mapping from the dark ages
VANETTI, ELENA
2021/2022
Abstract
This work investigates the potential for testing models of gravity with intensity mapping experiments observing the cosmic Dark Ages. Fluctuations in the brightness temperature of the 21 cm line of neutral hydrogen allow to reconstruct the HI distribution and trace the growth of structures across a wide range of scales and redshifts, for the most part yet to be explored. Observations at high redshifts z ∼ 30 − 200, however challenging, present numerous advantages and are in principle a high precision cosmological probe. Indeed, the growth of overdensities is still well described by linear perturbation theory and neutral hydrogen can be considered as an unbiased tracer of the underlying matter distribution, furthermore the signal is free of complications due to hardtomodel astrophysical processes. All of this makes it possible to give an analytical description of the signal and isolate the cosmological information. This thesis aims to generalize existing works on intensity mapping forecasts and develop a formalism and code to compute the angular power spectrum of 21 cm fluctuations during the Dark Ages and constrain the growth of structure. We produce forecasts for the ability of future groundbased radio interferometers, as well as predictions for the proposed radio array on the far side of the Moon, to constrain models of gravity.File  Dimensione  Formato  

Vanetti_Elena.pdf
Riservato
Dimensione
1.49 MB
Formato
Adobe PDF

1.49 MB  Adobe PDF 
The text of this website © Università degli studi di Padova. Full Text are published under a nonexclusive license. Metadata are under a CC0 License
https://hdl.handle.net/20.500.12608/41617