Rulevar 501 can disable research completly.

When you buy a research field and pay its price in either PP or in Resource (regimeslots) points you directly acquire it.

Research fields can be limited to certain peoples and can have different costs in PP/Resource for different peoplegroups of the people of the regime buying the research.

Research fields can also have pre-requisite researchfields that must first be researched before it can be researched.