$Euclid$: The search for primordial features

M Ballardini , Y Akrami , F Finelli , D Karagiannis , B Li , Y Li , Z Sakr (1) , D Sapone , A Achúcarro , M Baldi , N Bartolo , G Cañas-Herrera , S Casas , R Murgia , H.-A Winther , M Viel , A Andrews , J Jasche (2) , G Lavaux (2) , D.K Hazra , D Paoletti , J Valiviita , A Amara , S Andreon , N Auricchio , P Battaglia , D Bonino , E Branchini , M Brescia , J Brinchmann , S Camera , V Capobianco , C Carbone , J Carretero , M Castellano , S Cavuoti , A Cimatti , G Congedo , L Conversi (3) , Y Copin (4) , L Corcione , F Courbin , H.M Courtois (4) , A da Silva , H Degaudenzi , F Dubath , X Dupac , M Farina , S Farrens (5) , M Frailis , E Franceschi , M Fumana , S Galeotta , B Gillis , C Giocoli , A Grazian , F Grupp , S.V.H Haugan , W Holmes , F Hormuth , A Hornstrup , P Hudelot (2) , K Jahnke , S Kermiche (6) , A Kiessling , M Kunz , H Kurki-Suonio , P.B Lilje , V Lindholm , I Lloro , E Maiorano , O Mansutti , O Marggraf , N Martinet (7) , F Marulli , R Massey , E Medinaceli , S Mei (8) , Y Mellier (2) , M Meneghetti , E Merlin , G Meylan , M Moresco , L Moscardini , E Munari , S.-M Niemi , C Padilla , S Paltani , F Pasian , K Pedersen , W.J Percival , V Pettorino (5) , S Pires (5) , G Polenta , M Poncet (9) , L.A Popa , L Pozzetti , F Raison , A Renzi , J Rhodes , G Riccio , E Romelli , M Roncarelli , R Saglia , B Sartoris , T Schrabback , A Secroun (6) , G Seidel , S Serrano , C Sirignano , G Sirri , L Stanco , J.-L Starck (5) , C Surace (7) , P Tallada-Crespí , A.N Taylor , I Tereno , R Toledo-Moreo , F Torradeflot , I Tutusaus (1) , E.A Valentijn , L Valenziano , T Vassallo , A Veropalumbo , Y Wang , J Weller , G Zamorani , J Zoubian (6) , V Scottez (2, 10)

1 IRAP - Institut de recherche en astrophysique et planétologie
2 IAP - Institut d'Astrophysique de Paris
3 ESA - Agence Spatiale Européenne = European Space Agency
4 IP2I Lyon - Institut de Physique des 2 Infinis de Lyon
5 AIM (UMR7158 / UMR_E_9005 / UM_112) - Astrophysique Interprétation Modélisation
6 CPPM - Centre de Physique des Particules de Marseille
7 LAM - Laboratoire d'Astrophysique de Marseille
8 APC (UMR_7164) - AstroParticule et Cosmologie
9 CNES - Centre National d'Études Spatiales [Toulouse]
10 METRICS - Evaluation des technologies de santé et des pratiques médicales - ULR 2694

Primordial features, in particular oscillatory signals, imprinted in the primordial power spectrum of density perturbations represent a clear window of opportunity for detecting new physics at high-energy scales. Future spectroscopic and photometric measurements from the $Euclid$ space mission will provide unique constraints on the primordial power spectrum, thanks to the redshift coverage and high-accuracy measurement of nonlinear scales, thus allowing us to investigate deviations from the standard power-law primordial power spectrum. We consider two models with primordial undamped oscillations superimposed on the matter power spectrum, one linearly spaced in $k$-space the other logarithmically spaced in $k$-space. We forecast uncertainties applying a Fisher matrix method to spectroscopic galaxy clustering, weak lensing, photometric galaxy clustering, cross correlation between photometric probes, spectroscopic galaxy clustering bispectrum, CMB temperature and $E$-mode polarization, temperature-polarization cross correlation, and CMB weak lensing. We also study a nonlinear density reconstruction method to retrieve the oscillatory signals in the primordial power spectrum. We find the following percentage relative errors in the feature amplitude with $Euclid$ primary probes for the linear (logarithmic) feature model: 21% (22%) in the pessimistic settings and 18% (18%) in the optimistic settings at 68.3% confidence level (CL) using GC$_{\rm sp}$+WL+GC$_{\rm ph}$+XC. Combining all the sources of information explored expected from $Euclid$ in combination with future SO-like CMB experiment, we forecast ${\cal A}_{\rm lin} \simeq 0.010 \pm 0.001$ at 68.3% CL and ${\cal A}_{\rm log} \simeq 0.010 \pm 0.001$ for GC$_{\rm sp}$(PS rec + BS)+WL+GC$_{\rm ph}$+XC+SO-like both for the optimistic and pessimistic settings over the frequency range $(1,\,10^{2.1})$.

Domains: Astrophysics [astro-ph]

M Ballardini, Y Akrami, F Finelli, D Karagiannis, B Li, et al.. $Euclid$: The search for primordial features. Astron.Astrophys., 2024, 683, pp.A220. ⟨10.1051/0004-6361/202348162⟩. ⟨hal-04237840⟩