The paper by Deng Wang, published in the Instituto de Física Corpuscular (CSIC-Universitat de València), explores the use of DESI BAO (Baryon Acoustic Oscillation) observations to probe new physics on cosmological scales. The study constraints five popular cosmological scenarios: inflation, modified gravity, annihilating dark matter, interacting dark energy, and massive sterile neutrinos. Using a combination of BICEP/Keck array, cosmic microwave background (CMB), and DESI data, the authors obtain 1σ and 2σ constraints on the tensor-to-scalar ratio, indicating evidence for primordial gravitational waves. They also find a 2.4σ deviation from general relativity, a 12% reduction in the dark matter annihilation cross-section, a 1.3σ hint of positive interaction between dark matter and dark energy, and a 2σ constraint on the effective number of relativistic degrees of freedom and the effective mass of sterile neutrinos. The study highlights the potential of DESI observations to further explore the nature of inflation, dark matter, dark energy, and neutrinos, and to test the validity of general relativity on cosmological scales.The paper by Deng Wang, published in the Instituto de Física Corpuscular (CSIC-Universitat de València), explores the use of DESI BAO (Baryon Acoustic Oscillation) observations to probe new physics on cosmological scales. The study constraints five popular cosmological scenarios: inflation, modified gravity, annihilating dark matter, interacting dark energy, and massive sterile neutrinos. Using a combination of BICEP/Keck array, cosmic microwave background (CMB), and DESI data, the authors obtain 1σ and 2σ constraints on the tensor-to-scalar ratio, indicating evidence for primordial gravitational waves. They also find a 2.4σ deviation from general relativity, a 12% reduction in the dark matter annihilation cross-section, a 1.3σ hint of positive interaction between dark matter and dark energy, and a 2σ constraint on the effective number of relativistic degrees of freedom and the effective mass of sterile neutrinos. The study highlights the potential of DESI observations to further explore the nature of inflation, dark matter, dark energy, and neutrinos, and to test the validity of general relativity on cosmological scales.