The paper discusses the possibility of sterile neutrinos as dark matter, focusing on the scenario where they are the dominant component of dark matter. The authors re-examine the standard electroweak theory with the addition of right-handed or sterile neutrinos, which has been extensively studied in the context of hot dark matter. They find that sterile neutrinos can also be the dark matter in the form of warm dark matter, with a mass scale of around 0.1 - 1.0 keV. This mass range is crucial for determining the large-scale structure of the universe, leading to a structure formation scenario that may offer advantages over both hot and cold dark matter models. The paper also explores the production mechanisms of sterile neutrinos through neutrino oscillations and their implications for the dynamics of the universe, including the formation of structures and the observed properties of galaxies and clusters. The authors conclude that warm dark matter, particularly with sterile neutrinos, has several advantages over cold or hot dark matter, such as smaller pairwise velocity dispersions and earlier galaxy formation, making it a promising candidate for dark matter.The paper discusses the possibility of sterile neutrinos as dark matter, focusing on the scenario where they are the dominant component of dark matter. The authors re-examine the standard electroweak theory with the addition of right-handed or sterile neutrinos, which has been extensively studied in the context of hot dark matter. They find that sterile neutrinos can also be the dark matter in the form of warm dark matter, with a mass scale of around 0.1 - 1.0 keV. This mass range is crucial for determining the large-scale structure of the universe, leading to a structure formation scenario that may offer advantages over both hot and cold dark matter models. The paper also explores the production mechanisms of sterile neutrinos through neutrino oscillations and their implications for the dynamics of the universe, including the formation of structures and the observed properties of galaxies and clusters. The authors conclude that warm dark matter, particularly with sterile neutrinos, has several advantages over cold or hot dark matter, such as smaller pairwise velocity dispersions and earlier galaxy formation, making it a promising candidate for dark matter.