4 problems

The universal cork conjecture
Universal cork conjecture. There is no universal cork, i.e. no cork $(U,f_U)$ relating every exotic pair of simply-connected, closed $4$ -manifolds.
open4-manifolds 4-manifold-topology corks
0 responses
011
The disc embedding conjecture
Disc embedding conjecture. The circles $f_i(S^1)$ bound disjointly embedded discs in $M$ with transverse spheres, inducing the same framing on $f_i(S^1)$ as the $f_i$ .
open4-manifold-topology surgery-theory
0 responses
06
The topological 5-dimensional s-cobordism conjecture
$s$ -cobordism conjecture. There is a homeomorphism
open4-manifold-topology surgery-theory
0 responses
07
Y. Matsumoto's 11/8-conjecture for smooth 4-manifolds
Matsumoto's $11/8$ -conjecture. The inequality
open4-manifold-topology intersection-forms smooth-4-manifolds
0 responses
03

The universal cork conjecture