PAPER / ARXIV:2609.09340
William Ortolá Leonard , Alex Krolewski , Zachary Slepian , Alessandro Greco , Simon May , J. Aguilar , S. Ahlen , O. Alves , A. Aviles , F. Beutler , D. Bianchi , D. Brooks , A. Carnero Rosell , T. Claybaugh , A. de la Macorra , Biprateep Dey , S. Ferraro , J. E. Forero-Romero , E. Gaztañaga , Satya Gontcho A Gontcho , G. Gutierrez , K. Honscheid , D. Huterer , M. Ishak , S. Juneau , T. Karim , R. Kehoe , D. Kirkby , O. Lahav , M. Landriau , L. Le Guillou , M. Manera , A. Meisner , R. Miquel , J. A. Newman , E. Paillas , W. J. Percival , F. Prada , I. Pérez-Ràfols , C. Ravoux , R. Ruggeri , L. Samushia , E. Sanchez , C. Saulder , D. Schlegel , J. H. Silber , M. Siudek , G. Tarlé , B. A. Weaver
RESUMO
We present the connected even-parity galaxy 4-Point Correlation Function (4PCF) of DESI Year 1 (Y1) Luminous Red Galaxies (LRGs). This is one of the first measurements of the connected 4PCF on data, and shows a clear detection at $\sim$12 to 17$\sigma$ in the full-sky analysis. We test the robustness of the signal by varying three factors: hemisphere (north vs. south), redshift range (either the full range $0.4 < z < 1.1$ or the higher-number-density interval $0.4 < z < 0.8$), and sample completeness (the full sample vs. only the most complete regions within the number density-motivated cut). Finally, we cross-correlate different patches that are spatially well-separated, and thus should have largely independent noise. This approach, at leading order, is able to remove mismatch between the covariance matrix of the data and that of the mocks; however, in certain cases at the cost of sensitivity. We find $\sim$15$\sigma$ evidence for an even-parity 4PCF in this approach. Overall, the studies of the 4PCF presented here probe sensitively any mismatch between mock catalogs and data, and also open up the prospect of fitting a model, constraining cosmological parameters and galaxy biases, and searching for Baryon Acoustic Oscillation (BAO) features.
NO MESMO MAPA