I thought it would be nice if we had a reference for infinite combos used modern.
I've put together this list along with a script for creating this page. So please feel free to add your infinite combos below and I'll start adding them here. If you can try to add their result and perhaps a primer if there is a deck using the combo.
To be clear, we want combos that can go on indefinitely. So nothing like March of the Machines + Mycosynth Lattice. Those are two static abilities, while making an interesting combo, they are not infinite. A combo like Harrow + Uyo, Silent Prophet is fine. Sure you'll run out of lands in your deck, but no matter how many basics are in there the combo could be infinitely repeated.
Add combos below and happy brewing.
Please point out any errors you catch. I tried to make sure my data entry was correct, but more eyes can usually spot more mistakes.
I do have some enhancements for this list, but haven't created yet.
Perhaps add a list of the mandatory loops.
Add a listing for cards that abuse various infinite states. For example Altar of the Brood changes ETB Creatures into Mill.
Pitiless Plunderer + Drowner of Hope soulbonded with Deadeye Navigator gives infinite Eldrazi Scion tokens, and therefore infinite mana of any variety because of Pitiless Plunderer triggering off token creatures dying, so you can sac them for infinite Treasure tokens.