12 citations · 30 across the 6 of their papers we have counts for
6 papers
Non-Uniqueness of Minimal Superpermutations
Nathaniel Johnston
We examine the open problem of finding the shortest string that contains each of the n! permutations of n symbols as contiguous substrings (i.e., the shortest superpermutation on n…
Generation of Mapping Cones from Small Sets
Nathaniel Johnston, Łukasz Skowronek, Erling Størmer
We answer in the affirmative a recently-posed question that asked if there exists an "untypical" convex mapping cone -- i.e., one that does not arise from the transpose map and the…
Norms and Cones in the Theory of Quantum Entanglement
Nathaniel Johnston
There are various notions of positivity for matrices and linear matrix-valued maps that play important roles in quantum information theory. The cones of positive semidefinite matri…
The B36/S125 "2x2" Life-Like Cellular Automaton
Nathaniel Johnston
The B36/S125 (or "2x2") cellular automaton is one that takes place on a 2D square lattice much like Conway's Game of Life. Although it exhibits high-level behaviour that is similar…
The Complexity of the Puzzles of Final Fantasy XIII-2
Nathaniel Johnston
We analyze the computational complexity of solving the three "temporal rift" puzzles in the recent popular video game Final Fantasy XIII-2. We show that the Tile Trial puzzle is NP…
A Family of Norms With Applications In Quantum Information Theory II
Nathaniel Johnston, David W. Kribs
We consider the problem of computing the family of operator norms recently introduced in arXiv:0909.3907. We develop a family of semidefinite programs that can be used to exactly c…