Are current neutrino mass constraints reliable? insights from full-shape analyses

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Hernan E. Noriega

henoriega@icf.unam.mx

ICF & IF - UNAM

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5 Dec 2024

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Cosmology on the Beach

Hernán E. Noriega, ICF & IF - UNAM

2/6

Taken from DESI Collaboration: 2404.03002, 2411.12022

Neutrino mass constraints

LCDM: places very tight constraints, creating tension with particle physics results.

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Neutrino affects P(k) in two ways:

1. Background: the overall energy density.
2. Suppression: reduces power on small scales.

Such tight bounds are primarily due to strong constraints on H0 from DESI.

DESI gets a higher H0 compared to CMB [point (1)].

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Hernán E. Noriega, ICF & IF - UNAM

Hernán E. Noriega, ICF & IF - UNAM

3/6

Results on individuals bins of (e)BOSS

Noiseless synthetic data: was generated based on Planck cosmology and has the same properties of the real data

Strong projection effects on the neutrino mass!

The distributions do not recover the expected values.

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Noriega and Aviles 2407.06117

Insights from full-shape

Hernán E. Noriega, ICF & IF - UNAM

Hernán E. Noriega, ICF & IF - UNAM

4/6

Bayesian vs frequentist profile likelihood (PL) on the noiseless synthetic eBOSS data

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• Improvements can be made by adding the so-called Jeffrey priors, which partially cancel the Laplace effects associated with projections.

• Neutrinos exhibit significant degeneracies with parameters influenced by background evolution (peak shift to 0).

Insights from full-shape

Noriega and Aviles 2407.06117

Hernán E. Noriega, ICF & IF - UNAM

5/6

Most of the neutrino information comes from the wiggles rather than the broadband, contrary to what has been believed for decades!

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Frankenstein: Localization of the neutrino signal

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BB00W00 and BB05W05 are control samples, while the rest are Frankensteins.

Noriega and Aviles 2407.06117

Hernán E. Noriega, UNAM: ICF & IF

Hernán E. Noriega, ICF & IF - UNAM

6/6

From full-shape insights

• Neutrino mass constraints suffer from projection effects, which are influenced by background evolution

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• The projection effects do not alleviate with the addition of more information (shown in our paper)

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Broadband vs wiggles

• We discovered that, contrary to common belief, information about neutrino mass is primarily derived from the relative amplitude of the wiggles, rather than from broadband suppression.

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• Isolating the neutrino mass signal is crucial for developing a robust alternative method to extract mass information

Conclusions