The DESI year one observations provide valuable insights into cosmological physics. Using DESI BAO data combined with BICEP/Keck array and cosmic microwave background (CMB) data, researchers constrain five popular cosmological models: inflation, modified gravity (MG), annihilating dark matter (ADM), interacting dark energy (IDE), and massive sterile neutrinos. The results show a 2σ evidence for primordial gravitational waves, with the tensor-to-scalar ratio r₀.₀₅ constrained to 0.0176₋₀.₀₁₃₀⁺₀.₀₀₇₀ and 0.018₋₀.₀₁₇⁺₀.₀₂₀. The CMB+DESI data also indicates a 2.4σ deviation from general relativity (GR), shrinks the dark matter annihilation cross-section by 12%, and provides a 1.3σ hint of a positive interaction between dark matter and dark energy. Additionally, the effective number of relativistic degrees of freedom N_eff is constrained to 3.16₋₀.₁₁⁺₀.₂₆, and the effective mass of sterile neutrinos is less than 0.52 eV at 2σ. These results suggest that DESI data can help explore the nature of inflation, dark matter, dark energy, and neutrinos, and test the validity of GR on cosmological scales. The study highlights the importance of high-precision observations in addressing cosmological tensions and anomalies.The DESI year one observations provide valuable insights into cosmological physics. Using DESI BAO data combined with BICEP/Keck array and cosmic microwave background (CMB) data, researchers constrain five popular cosmological models: inflation, modified gravity (MG), annihilating dark matter (ADM), interacting dark energy (IDE), and massive sterile neutrinos. The results show a 2σ evidence for primordial gravitational waves, with the tensor-to-scalar ratio r₀.₀₅ constrained to 0.0176₋₀.₀₁₃₀⁺₀.₀₀₇₀ and 0.018₋₀.₀₁₇⁺₀.₀₂₀. The CMB+DESI data also indicates a 2.4σ deviation from general relativity (GR), shrinks the dark matter annihilation cross-section by 12%, and provides a 1.3σ hint of a positive interaction between dark matter and dark energy. Additionally, the effective number of relativistic degrees of freedom N_eff is constrained to 3.16₋₀.₁₁⁺₀.₂₆, and the effective mass of sterile neutrinos is less than 0.52 eV at 2σ. These results suggest that DESI data can help explore the nature of inflation, dark matter, dark energy, and neutrinos, and test the validity of GR on cosmological scales. The study highlights the importance of high-precision observations in addressing cosmological tensions and anomalies.