1,516 research outputs found
Analytic Approximations for the Primordial Power Spectrum with Israel Junction Conditions
This work compares cosmological matching conditions used in approximating
generic pre-inflationary phases of the universe. We show that the joining
conditions for primordial scalar perturbations assumed by Contaldi et al. are
inconsistent with the physically motivated Israel junction conditions, however,
performing general relativistic matching with the aforementioned constraints
results in unrealistic primordial power spectra. Eliminating the need for
ambiguous matching, we look at an alternative semi-analytic model for producing
the primordial power spectrum allowing for finite duration cosmological phase
transitions.Comment: 21 pages, 10 figures. To be submitted to PR
Fully Bayesian Forecasts with Evidence Networks
Sensitivity forecasts inform the design of experiments and the direction of
theoretical efforts. We argue that to arrive at representative results Bayesian
forecasts should marginalize their conclusions over uncertain parameters and
noise realizations rather than picking fiducial values. However, this is
computationally infeasible with current methods. We thus propose a novel
simulation-based forecasting methodology, which we find to be capable of
providing expedient rigorous forecasts without relying on restrictive
assumptions.Comment: 5 pages + references, 1 figure. Submitted to PR
Improved cosmological fits with quantized primordial power spectra
We observationally examine cosmological models based on primordial power
spectra with quantized wavevectors. Introducing a linearly quantized power
spectrum with and spacing provides a better fit to the Planck
2018 observations than the concordance baseline, with .
Extending the results of Lasenby et al [1], we show that the requirement for
perturbations to remain finite beyond the future conformal boundary in a
universe containing dark matter and a cosmological constant results in a
linearly quantized primordial power spectrum. It is found that the infrared
cutoffs for this future conformal boundary quantized cosmology do not provide
cosmic microwave background power spectra compatible with observations, but
future theories may predict more observationally consistent quantized spectra.Comment: 14 pages, 8 figures, prepared for submission to PR
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