Difference between revisions of "Forecastfiso planck"
(Created page with "== Overview == We can improve constraints on isocurvature perturbations from Planck with observations from S4. Here we consider the curvaton model: there is one isocurvature mod...") |
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To check that we are getting reasonable results, we run the Fisher matrix with LCDM+Mnu+f_iso with Planck noise levels, beams, and fsky as specified in previous forecast checks. | To check that we are getting reasonable results, we run the Fisher matrix with LCDM+Mnu+f_iso with Planck noise levels, beams, and fsky as specified in previous forecast checks. | ||
| − | We tested for | + | We tested for fiducial cosmology f_iso=0 with CDM isocurvature modes; The following constraints use TT/EE/TE lensed spectra. |
The following are the constraints we get: | The following are the constraints we get: | ||
| Line 19: | Line 19: | ||
| | | | ||
| LCDM+Mnu+f_iso=0 | | LCDM+Mnu+f_iso=0 | ||
| − | |||
|- | |- | ||
|och2 | |och2 | ||
| 0.001523 | | 0.001523 | ||
| − | |||
|- | |- | ||
|obh2 | |obh2 | ||
| 0.000163 | | 0.000163 | ||
| − | |||
|- | |- | ||
|onuh2 | |onuh2 | ||
| 0.005396 | | 0.005396 | ||
| − | |||
|- | |- | ||
|10^9 As | |10^9 As | ||
| 0.2589 | | 0.2589 | ||
| − | |||
|- | |- | ||
|ns | |ns | ||
| 0.00486 | | 0.00486 | ||
| − | |||
|- | |- | ||
|tau | |tau | ||
| 0.0597 | | 0.0597 | ||
| − | |||
|- | |- | ||
|hubble | |hubble | ||
| 4.84 | | 4.84 | ||
| − | |||
|- | |- | ||
|f_iso | |f_iso | ||
| 0.00391 | | 0.00391 | ||
| − | |||
|} | |} | ||
We are doing a literature search to find previous forecasts that uses a similar parameterization (as opposed to the alpha or beta parameterization) to compare our results. | We are doing a literature search to find previous forecasts that uses a similar parameterization (as opposed to the alpha or beta parameterization) to compare our results. | ||
Revision as of 09:31, 27 May 2016
Overview
We can improve constraints on isocurvature perturbations from Planck with observations from S4.
Here we consider the curvaton model: there is one isocurvature mode: the CDM isocurvature, and the spectral index of the CDM mode is the same as that of the adiabatic scalar perturbations, n_s. In this scenario, the CDM mode is either totally correlated or anti-correlated with the adiabatic perturbations.
The parameter we are constraining is f_iso, the primordial fraction of CDM isocurvature amplitude to the scalar perturbation amplitude. Specifically, the final spectra is
Cl^{tot} = Cl^{ad} + f_iso^2 Cl^{cdm iso} + 2* f_iso * Cl^{correlated}
where Cl^{cdm iso} is generated such that it has the same primordial power A_s as the scalar perturbations, and similarly for Cl^{correlated}.
Planck test
To check that we are getting reasonable results, we run the Fisher matrix with LCDM+Mnu+f_iso with Planck noise levels, beams, and fsky as specified in previous forecast checks.
We tested for fiducial cosmology f_iso=0 with CDM isocurvature modes; The following constraints use TT/EE/TE lensed spectra.
The following are the constraints we get:
| LCDM+Mnu+f_iso=0 | |
| och2 | 0.001523 |
| obh2 | 0.000163 |
| onuh2 | 0.005396 |
| 10^9 As | 0.2589 |
| ns | 0.00486 |
| tau | 0.0597 |
| hubble | 4.84 |
| f_iso | 0.00391 |
We are doing a literature search to find previous forecasts that uses a similar parameterization (as opposed to the alpha or beta parameterization) to compare our results.
