Meindertsma, Edo Arend (2026) Impact of Baryonic Feedback on Cosmological Inference from Lensed CMB Power Spectra. Bachelor's Thesis, Astronomy.
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Abstract
Using Markov-chain Monte Carlo (MCMC) we analyze the polarization power spectra of the cosmic microwave background (CMB) power spectra to find out how using incorrect baryonic models biases the inferred cosmological parameters when calculations are done up to multipole l = 5000. We use data simulated by CAMB to find that τ and ln(A_s) can have biases of more than 2σ, and that the other cosmological parameters, H_0, Ω_{b,0}h², Ω_{c,0}h², are also biased, while n_s is relatively unbiased. Furthermore, the biases are proportional to the difference in suppression of the lensing power spectrum C_l^{κκ} between the true baryonic model, and the model used for forecasting. This highlights the uncertainty in current baryonic models, and the effect that it will have when analyses are done with next-generation research such as from the Simons Observatory, which will be able to measure the CMB power spectra for these high multipoles.
| Item Type: | Thesis (Bachelor's Thesis) |
|---|---|
| Supervisor name: | Meerburg, P.D. and Vecchi, M. |
| Degree programme: | Astronomy |
| Thesis type: | Bachelor's Thesis |
| Language: | English |
| Date Deposited: | 20 Jan 2026 09:35 |
| Last Modified: | 20 Jan 2026 09:35 |
| URI: | https://fse.studenttheses.ub.rug.nl/id/eprint/37212 |
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