Ellen Hammatt (Victoria University of Wellington) – Towards quantum limits for subelliptic operators

In this talk we investigate what happens when we take concepts from computable structure theory and forbid the use of unbounded search. In other words, we discuss the primitive recursive content of computable structure theory. The central definition is that of punctual structures, introduced by Kalimullin, Melnikov and Ng in 2017. A common theme is that new techniques are required in the primitive recursive analogue of computable structure theory concepts. We also discuss a degree structure within punctual presentations which is induced by primitive recursive isomorphisms. This degree structure is a new concept that does not arise in computable structure theory.