I'm trying to learn about D-modules for computing intersection cohomology but I'm having trouble coming up with explicit constructions of D-modules on projective varieties. Since this is an involved process, I'll split this up into multiple questions: 1. How do I construct D-modules over complex projective space 2. How do I construct D-modules over smooth projective varieties 3. How can I use the constructions from (1) to find D-modules with geometric support on singular varieties? My goal is to start looking at D-modules on Fermat curves $$ \text{Proj}\left( \frac{\mathbb{C}[x,y,z]}{x^n + y^n - z^n} \right) $$ and answer the question I raised [here][1] [1]: https://mathoverflow.net/questions/244810/where-should-i-look-for-computing-the-intersection-homology-of-projective-variet