8 problems

Ollinger's conjecture. The $8$-polyomino tiling problem is undecidable.

Let $(\mathcal{T},\sigma,M)$ be a primitive substitution tiling system of $\mathbb{R}^d$ with finite local complexity. Call it conservation-forced when it satisfies the conservatio…

Let $P$ denote the class of decision problems solvable in polynomial time, and let $NP$ denote the class of decision problems whose proposed solutions can be verified in polynomial…

Beauquier–Nivat conjecture. The $2$-polyomino tiling problem is decidable.

Orthonormal wavelet implies wavelet-set conjecture. For each pair $(B,\Gamma^*)$ such that there exists a $(B,\Gamma^*)$ orthonormal wavelet, there exists an $(A,\Gamma)$ wavelet s…

Let $\Lambda$ be the union of all vertices and edges of all drawn triangles in a periodic triangle tiling. Let $\delta$ be any periodic closed trajectory of the corresponding trian…

Let $ABC$ be a triangle that is $N$-tiled, meaning it is tiled by $N$ congruent triangles. Let the tile have angles $\alpha$ and $\beta$ satisfying … and suppose that $\alpha$ is n…

The problem asks for the positive integers $N$ for which some triangle can be cut into $N$ congruent triangles. Soifer's Problem 6.7 conjecture. The solution should be that $N$ mus…