P vs. BPP
Conjecture Can all problems that can be computed by a probabilistic Turing machine (with error probability < 1/3) in polynomial time be solved by a de...
Refuting random 3SAT-instances on $O(n)$ clauses (weak form)
Conjecture For every rational $\epsilon > 0$ and every rational $\Delta$, there is no polynomial-time algorithm for the following problem. Given is a...
Rank vs. Genus
Question Is there a hyperbolic 3-manifold whose fundamental group rank is strictly less than its Heegaard genus? How much can the two differ by?...
Which compact boundaryless 3-manifolds embed smoothly in the 4-sphere?
Problem Determine a computable set of invariants that allow one to determine, given a compact boundaryless 3-manifold, whether or not it embeds smooth...
Is there an algorithm to determine if a triangulated 4-manifold is combinatorially equivalent to the 4-sphere?
Problem Is there an algorithm which takes as input a triangulated 4-manifold, and determines whether or not this manifold is combinatorially equivalen...
Unsolvability of word problem for 2-knot complements
Problem Does there exist a smooth/PL embedding of $S^2$ in $S^4$ such that the fundamental group of the complement has an unsolvable word problem?...
Several ways to apply a (multivalued) multiargument function to a family of filters
Problem Let $\mathcal{X}$ be an indexed family of filters on sets. Which of the below items are always pairwise equal? 1. The funcoid corresponding t...
Rendezvous on a line
Problem Two players start at a distance of 2 on an (undirected) line (so, neither player knows the direction of the other) and both move at a maximum ...
For every non-equilateral triangle T, show that it is possible to color the plane with three colors so that there is no
v1.3 research notesGraham: For every non-equilateral triangle T, show that it is possible to color the plane with three colors so that there is no monochromatic (congrue...
Is every polygonal room in the plane illuminable from some point
v1.3 research notesStraus: Is every polygonal room in the plane illuminable from some point? See this....
What is the (homogeneous adjacency) spectrum of the Fano plane
v1.3 research notes/Clark : What is the (homogeneous adjacency) spectrum of the Fano plane?...
Integer-distance point sets
v1.3 research notesDo there exist seven planar points in general position—no three collinear and no four concyclic—such that every pairwise distance is an integer?...