Modified Gravity Constraints from the Full Shape Modeling of Clustering Measurements from DESI 2024
M. Ishak, J. Pan, R. Calderon, K. Lodha, G. Valogiannis, A. Aviles, G. Niz, L. Yi, C. Zheng, C. Garcia-Quintero, A. de Mattia, L. Medina-Varela, J. L. Cervantes-Cota, U. Andrade, D. Huterer, H. E. Noriega, G. Zhao, A. Shafieloo, W. Fang, S. Ahlen, D. Bianchi, D. Brooks, E. Burtin, E. Chaussidon, T. Claybaugh, S. Cole, A. de la Macorra, Arjun Dey, K. Fanning, S. Ferraro, A. Font-Ribera, J. E. Forero-Romero, E. Gaztañaga, H. Gil-Marín, S. Gontcho A Gontcho, G. Gutierrez, C. Hahn, K. Honscheid, C. Howlett, S. Juneau, D. Kirkby, T. Kisner, A. Kremin, M. Landriau, L. Le Guillou, A. Leauthaud, M. E. Levi, A. Meisner, R. Miquel, J. Moustakas, J. A. Newman, N. Palanque-Delabrouille, W. J. Percival, C. Poppett, F. Prada, I. Pérez-Ràfols, A. J. Ross, G. Rossi, E. Sanchez, D. Schlegel, M. Schubnell, H. Seo, D. Sprayberry, G. Tarlé, M. Vargas-Magana, B. A. Weaver, R. H. Wechsler, C. Yèche, P. Zarrouk, R. Zhou, H. Zou
TL;DR
This work tests General Relativity on cosmological scales by analyzing DESI DR1 full-shape clustering in combination with Planck CMB, DES Y3, SN, and BBN data. It adopts multiple MG parameterizations, including time- and scale-dependent $\mu(a,k)$, $\Sigma(a,k)$, and $\eta(a,k)$, as well as EFT/α-basis Horndeski frameworks, to quantify deviations from GR in both $\Lambda$CDM and $w_0w_a$CDM backgrounds. Across functional and redshift-redshift+scale binning parameterizations, all MG parameters are consistent with GR, with the tightest constraints achieved when DESI is combined with CMB (LoLLiPoP/HiLLiPoP) and DESY3/DESSNY5 SN data; notably, the Planck lensing tension in $\Sigma_0$ is mitigated with newer likelihoods. The analysis also finds a persistent indication of dynamical dark energy in the $w_0w_a$CDM background, while EFT/α-basis constraints remain broadly GR-compatible, with mild hints for nonzero braiding. Overall, DESI one-year data demonstrate competitive MG constraints, and future DESI data are expected to significantly improve sensitivity to gravity theories on cosmological scales.
Abstract
We present cosmological constraints on deviations from general relativity (GR) from the first-year of clustering observations from Dark Energy Spectroscopic Instrument (DESI) in combination with other datasets. We first consider $μ(a,k)$-$Σ(a,k)$ modified gravity (MG) parametrization (as well as $η(a,k)$) in flat $Λ$CDM and $w_0 w_a$CDM backgrounds. Using a functional form for time-only evolution gives $μ_0=0.11^{+0.44}_{-0.54}$ from DESI(FS+BAO)+BBN and a wide prior on $n_{s}$. Using DESI(FS+BAO)+CMB+DESY3+DESY5-SN, we obtain $μ_0=0.05\pm 0.22$ and $Σ_0=0.008\pm 0.045$ in the $Λ$CDM background. In $w_0 w_a$CDM, we obtain $μ_0=-0.24^{+0.32}_{-0.28}$ and $Σ_0=0.006\pm 0.043$, consistent with GR, and still find a preference for dynamical dark energy with $w_0>-1$ and $w_a<0$. We then use binned forms in the 2 backgrounds starting with 2 bins in redshift and then adding 2 bins in scale for a total of 4 and 8 MG parameters, respectively. All MG parameters are found consistent with GR. We also find that the tension reported for $Σ_0$ with GR from Planck PR3 goes away when using LoLLiPoP+HiLLiPoP likelihoods. As noted previously, this seems to indicate the tension is related to CMB lensing anomaly in PR3 which is also resolved when using these likelihoods. We then constrain the class of Horndeski theory in both EFT-basis and $α$-basis. Assuming a power law for the non-minimal coupling function $Ω$, we obtain $Ω_0=0.012^{+0.001}_{-0.012}$ and $s_0=0.996^{+0.54}_{-0.20}$ from DESI(FS+BAO)+DESY5SN+CMB in a $Λ$CDM background, consistent with GR. Using the $α$-basis with no-braiding ($α_B=0$) gives $c_M<1.14$, in agreement with GR. However, we see a mild yet consistent indication for $c_B>0$ when $α_B$ is varied which will require further study to determine whether this is due to systematics or new physics. [Abridged]