Due to federal restrictions contained in the current National Defense Authorization Act, citizens of the People's Republic of China-including the special administrative regions of Hong Kong and Macau-as well as citizens of the Islamic Republic of Iran, the Democratic People's Republic of Korea (North Korea), and the Russian Federation, who are not Lawful Permanent Residents ("green card" holders) are prohibited from accessing facilities that support the mission, functions, and operations of national security laboratories and nuclear weapons production facilities, which includes Los Alamos National Laboratory. The Applied Mathematics and Plasma Physics (T-5) group within T-Division conducts research across a wide variety of topics, including fusion science, space plasma science, numerical analysis, computational imaging, optimization, environmental sciences, and the modeling of critical infrastructure (e.g., gas pipelines and electrical grids).