| Budget Amount *help |
¥5,200,000 (Direct Cost: ¥4,000,000、Indirect Cost: ¥1,200,000)
Fiscal Year 2014: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2013: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2012: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
|
|---|
| Outline of Final Research Achievements |
We investigated the structure of the real numbers and of its subsets from the points of view of combinatorial set theory and descriptive set theory. A main focus of this research was to carry out independence proofs, using the method of forcing, about aspects of sets of reals satisfying certain maximality properties, like maximal almost disjoint families, ultrafilters, gaps, and towers.
We obtained new results about cardinal invariants which are defined as the least size of such families with maximality properties, and their relationship with other classical cardinal invariants of the continuum, showing for example that the closed almost disjointness number can consistently be both larger and smaller than the unbounding number.
We also proved new results about the possible complexity of such families in the projective hierarchy, showing for example that the existence of a coanalytic maximal almost disjoint family is consistent with large unbounding number.
|
