The price of perfection
What it costs a finite quantum system to approach a perfect strategy it can never reach, and whether that cost can be computed.
Nine works in nineteen archived versions · latest release
The question
Answered Can that price be computed from a game’s rules?
Not in general.
The papersin reading order, with what each settled
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The uncomputable price of precision
Seth Douglas and Nidhal Mghirbi · version 4.0.0 · · 119 pages
For finite rational constraint-system games of quantum value one, the positive exponents of the least local dimension needed near perfect play are exactly the positive reals, with matched distillable-entanglement realizations; the lower and upper exponent pairs are exactly the pairs.
- Answered Can the rate at which the least dimension grows near perfect play be computed from a finite game’s rules?
- Answered Which lower and upper exponents can one fixed game have?
- Open Can a finite rational value-one game with no finite-dimensional perfect strategy have dimension exponent zero? posed here
- Open Is every positive usable-entanglement coefficient of a finite rational game limit-computable? posed here
- Open Which finite power exponents above one occur for a fixed finite rational game? posed here
- Open Which positive local-reset heat coefficients occur? posed here
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Uncomputable critical exponents
Seth Douglas and Nidhal Mghirbi · version 2.1.0 · · 64 pages
Translation-invariant nearest-neighbour quantum Hamiltonians whose critical gap exponents are exactly the nonnegative reals, already in two dimensions; and robust laws of noisy media that no effective inquiry can learn beyond .
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A beginning is worth one limit: robust unlearnable laws in noisy cellular automata
Seth Douglas and Nidhal Mghirbi · version 1.0.0 · · 19 pages
At equal depth, a computable law of a cellular automaton that has a beginning reaches one arithmetical level above any law on which its stationary states agree; at depth one, a rule started from cloned uniform noise realizes every value in as a robust law.
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An explicit nonlocal game of quantum value one that needs exponential entanglement
Nidhal Mghirbi and Seth Douglas · version 1.1.0 · · 93 pages
A binary linear system game with 1687 equations in 1993 variables, of quantum value one, in which winning with probability needs entanglement entropy , hence local dimension ; the exponent is sharp.
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The price of precision: usable entanglement in nonlocal games and the geometry of groups
Seth Douglas and Nidhal Mghirbi · version 1.1.0 · · 160 pages
For the game classes treated, the entanglement demand near perfect play diverges exactly when no finite-dimensional strategy is perfect; bounded demand is undecidable among games of value one; and the geometry of groups gives logarithmic, almost inverse-loss and intermediate laws.
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The price of unreachable perfection: dimension laws at every regular scale
Seth Douglas and Nidhal Mghirbi · version 1.0.1 · · 24 pages
The growth of the least dimension can be prescribed at every regular scale, not only along power laws. At every asymptotically flat scale the normalized endpoints are exactly the pairs, and a computable target can still lie outside every game’s profile.
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Matter that pays the price of perfection
Seth Douglas and Nidhal Mghirbi · version 1.0.0 · · 27 pages
Gapped translation-invariant lattices whose entanglement has any prescribed limit-computable logarithmic coefficient, and a referee cell that converts low energy into strategies for a nonlocal game. The game-driven material theorem is stated conditionally.
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Perfect play in a binary-scoring nonlocal game requires infinite dimension but only finite energy
Seth Douglas and Nidhal Mghirbi · version 2.0.0 · · 39 pages
A game with ten and eleven questions and at most six answers is won perfectly by an infinite-dimensional strategy and by no finite one, with dimension profile . Perfect play needs only finite energy: quanta per oscillator at best.
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The heat price of precision
Seth Douglas and Nidhal Mghirbi · version 1.0.0 · · 21 pages
For games whose usable-entanglement demand diverges, resetting locally before communicating forces divergent work, while bringing the systems back together before reset keeps the operating work bounded.
Posed by othersproblems printed by others that this line takes up
What is openfive questions
- Open Can a finite rational value-one game with no finite-dimensional perfect strategy have dimension exponent zero?
- Open Is every positive usable-entanglement coefficient of a finite rational game limit-computable?
- Open Which finite power exponents above one occur for a fixed finite rational game?
- Open Can cloned preparation be removed from the realization of robust unlearnable laws?
- Open Which positive local-reset heat coefficients occur?