DESI DR1 Ly{\alpha} 1D power spectrum: The Fast Fourier Transform estimator measurement

Understand

We present the one-dimensional Lyman-$\alpha$ forest power spectrum measurement derived from the data release 1 (DR1) of the Dark Energy Spectroscopic Instrument (DESI).

• The measurement of the Lyman-$\alpha$ forest power spectrum along the line of sight from high-redshift quasar spectra provides information on the shape of the linear matter power spectrum, neutrino masses, and the properties of dark matter.
• In this work, we use a Fast Fourier Transform (FFT)-based estimator, which is validated on synthetic data in a companion paper.
• Compared to the FFT measurement performed on the DESI early data release, we improve the noise characterization with a cross-exposure estimator and test the robustness of our measurement using various data splits.