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The Dark Energy and Massive Neutrino Universe (DEMNUni) campaign

Carmelita Carbone

Meeting “INAF USCVIII – General Assembly”, Galzignano, 14-18 Oct 2024

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DEMNUni simulations: labs for structure formation in 𝝂w₀w_aCDM scenarios

Credits: Tuccari, Sciacca, Vitello

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Improving non-linear modelling in the presence of massive neutrinos

CC et al 2016

Hot neutrino velocities, i.e. free streaming neutrinos, suppress structure formation on large scales

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Improving non-linear modelling in the presence of massive neutrinos

Parimbelli, CC et al 2022

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Halo Mass Function in the presence of massive neutrinos

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Cold Dark Matter and Neutrinos halo profiles

CDM overdensity profiles in haloes with masses M_h in different mass bins. Dashed lines correspond to a NFW density profile fit. Vertical dotted lines set the halo radii R₂₀₀ defined by an overdensity threshold Δ = 200 with respect to the mean background total matter density

Mean neutrino overdensity profiles for M_h > 10¹⁴ h−1M_⊙. The error bars correspond to 1σ dispersion around the calculated mean value of the overdensity at each radius. Fits to formula (dashed lines). Vertical dotted lines set the core radius (r_c parameter) obtained from the fit.

Hernández-Molinero, CC et al 2024

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3D-void size function: similarities and differences with the halo MF

The void size function

The halo mass function

According to the top-hat model, overdensities experience two main events during their evolution, turn-around and virialization. On the contrary, the top-hat evolution of underdensities is not characterised by any specifc event, they continue their outward-directed expansion forever. Therefore it is common to consider the shell-crossing condition as the event that characterises the void formation.

The threshold for collapse is necessary to take into account the fraction of underdensities that lie within larger overdensities, i.e. the void-incloud fraction. This class of underdensities will be squeezed out of existence by the larger collapsing overdensity that surrounds them [88]. Hence, in order to evaluate the fraction of fluctuations that will evolve in voids, we calculate the probability that a fluctuation of scale R (i.e. the fraction of random walks that) crosses delta_v, the void formation threshold, and have never crossed delta_c, the threshold for collapse, at any scale larger than R.

this void size function is known as the \volume conserving model", or Vdn. It corresponds to the SvdW model with the additional condition of

conserving volume, which basically shifts the void size function towards lower values.

(vii) Boundary ridge: As matter from the interior accumulates near the boundary, a ridge develops around the void.

(viii) Shell crossing: The transition from a quasi-linear towards a mature non-linear stage occurs as inner shells pass across outer

shells.

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The void size function

Number density
The multiplicity function:

fraction of fluctuations that become voids

Jacobian: from 𝜎 to mass interval

From Lagrangian to Eulerian space:

Sheth & Van de Weygaert 2004

Jennings et al. 2013

From mass scale to Lagrangian radius:

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3D-void abundance in DEMNUni: comparison among M_ν cosmologies

3D CDM-voids

z=0

In the presence of massive neutrinos, large CDM-voids become less abundant, and small CDM-voids more abundant than in LCDM.

The total number of voids increases with M_ν for CDM-voids and decreases for voids traced by haloes with a high-mass threshold.

z=0

3D halo-voids

The opposite happens for voids traced by highly biased objects: combination of neutrino impact on HMF and VSF

Kreish et al. 2019

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Void size function in DEMNUni simulations: sensitivity to DE & M_ν

Verza, CC et al 2023

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The halo bias within cosmic voids: galaxies in voids evolve differently

Verza, CC et al ApJL 2022

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CC et al 2016

Weak-Lensing and Integrated Sachs-Wolfe/Rees-Sciama maps

Box stacking technique

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Cuozzo, CC et al. 2024

ISWRS cross galaxies and CMB-Lensing in M_ν cosmologies

Thanks to simulations we found the M_ν-dependency of the sign-inversion of the ISWRSxLSS spectra

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Cosmic background neutrinos deflected by gravity

Beatriz Hernández-Molinero, CC et al 2024

To summarise, the lightest neutrinos are so ultra-relativistic that they to do not suffer deflection from gravity but, at the same time, they are not relativistic enough to achieve the same capture rate for Dirac and Majorana cases. This means that the capture rate in Ptolemy-like experiments will be sensitive to the neutrino nature, and gravity helps to increase that difference.

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The galaxy-halo connection in the presence of dynamical dark energy and massive neutrinos

Carella, CC et al. in prep

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DEMNUni main scientific results

First measurements of ISW-RS in the presence of M_ν and dynamical DE

Improved modelling of matter power spectrum in the presence of M_ν

First measurement and modelling of matter bispectrum in the presence of M_ν

Testing matter nonlinear models/emulators against Nbody measurement in the presence of M_ν and dynamical DE

Improving matter and velocity modelling in the presence of M_ν and dynamical DE

First measurements of void profiles from the void-CMB_lensing cross correlation in the presence of M_ν and dynamical DE

First measurements of the cosmic void correlation and void size function in the presence of M_ν and dynamical DE

Improved modelling of galaxy bias within cosmic voids

Improved modelling of ISWRS X GC/CMB-L in the presence of massive neutrinos

Improved multiplicity function for halos and voids

Improved cosmic neutrino background capture rates

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DEMNUni applications to Euclid

KP-CL-3 pre-launch paper-4 “Halo mass function and bias in non-standard models” of the Galaxy-Clusters SWG.�
KP-CL-3 pre-launch paper-1 “Calibration of the halo mass function in Λ(ν) cosmologies” Castro et al. A&A 671, A100 (2023)

KP-CMBX-2 pre-launch paper2 “CMBX Mock Simulations” in CMBX SWG.�
KP-JC-6 pre-launch paper-3 “Simulations & non-linearities beyond ΛCDM” joint Theory and Cosmo-SIM SWGs.�
KP-TH-1 pre-launch paper-6 “Euclid: Nonlinear spectroscopic clustering in beyond-ΛCDM scenarios with Euclid”, Theory SWG.�
CMBX-covariances: calibration of FLASK lognormal mocks against DEMNUni-CoV mocks

Priority models in CoS-SWG WP8: Non-standard models

KP-CL-2 “Euclid preparation: Determining the weak lensing mass accuracy and precision for galaxy clusters”, arXiv:2409.02783