Academic-turned-teacher (but still doing research as a hobby), interested in mathematical logic - specifically, computability theory and reverse mathematics, set theory, and abstract model theory. I'm also interested in other Nifty Things, in mathematics and elsewhere.

Since the SE system only allows temporary bounties, I am here informally "perma-bountying" the following ten questions, each for 1000 points (only a complete answer is guaranteed the bounty, so e.g. a partial answer to the unraveling question within the next week probably would get the standard 500-point bounty currently offered but probably would not get a further +500 reward):

• Geometry and topology:

  • involutive triangle centers

  • axiomatized function spaces

• Model theory:

  • ultrapowers and automorphisms

  • second-order Tarski-Vaughtification

• Descriptive set theory:

  • unraveling and determinacy

  • Banach game quantifier

• Set theory:

  • gently changing measure

  • second-order properties and ultrafilters

• Computability theory:

  • strong +1 hypothesis

  • cone property and e-degrees