1,519 research outputs found
Some new directions in infinite-combinatorial topology
We give a light introduction to selection principles in topology, a young
subfield of infinite-combinatorial topology. Emphasis is put on the modern
approach to the problems it deals with. Recent results are described, and open
problems are stated. Some results which do not appear elsewhere are also
included, with proofs.Comment: Small update
Selection principles in mathematics: A milestone of open problems
We survey some of the major open problems involving selection principles,
diagonalizations, and covering properties in topology and infinite
combinatorics. Background details, definitions and motivations are also
provided.Comment: Small update
The Classical Complexity of Boson Sampling
We study the classical complexity of the exact Boson Sampling problem where
the objective is to produce provably correct random samples from a particular
quantum mechanical distribution. The computational framework was proposed by
Aaronson and Arkhipov in 2011 as an attainable demonstration of `quantum
supremacy', that is a practical quantum computing experiment able to produce
output at a speed beyond the reach of classical (that is non-quantum) computer
hardware. Since its introduction Boson Sampling has been the subject of intense
international research in the world of quantum computing. On the face of it,
the problem is challenging for classical computation. Aaronson and Arkhipov
show that exact Boson Sampling is not efficiently solvable by a classical
computer unless and the polynomial hierarchy collapses to
the third level.
The fastest known exact classical algorithm for the standard Boson Sampling
problem takes time to produce samples for a
system with input size and output modes, making it infeasible for
anything but the smallest values of and . We give an algorithm that is
much faster, running in time and
additional space. The algorithm is simple to implement and has low constant
factor overheads. As a consequence our classical algorithm is able to solve the
exact Boson Sampling problem for system sizes far beyond current photonic
quantum computing experimentation, thereby significantly reducing the
likelihood of achieving near-term quantum supremacy in the context of Boson
Sampling.Comment: 15 pages. To appear in SODA '1
Mechanism Design for Team Formation
Team formation is a core problem in AI. Remarkably, little prior work has
addressed the problem of mechanism design for team formation, accounting for
the need to elicit agents' preferences over potential teammates. Coalition
formation in the related hedonic games has received much attention, but only
from the perspective of coalition stability, with little emphasis on the
mechanism design objectives of true preference elicitation, social welfare, and
equity. We present the first formal mechanism design framework for team
formation, building on recent combinatorial matching market design literature.
We exhibit four mechanisms for this problem, two novel, two simple extensions
of known mechanisms from other domains. Two of these (one new, one known) have
desirable theoretical properties. However, we use extensive experiments to show
our second novel mechanism, despite having no theoretical guarantees,
empirically achieves good incentive compatibility, welfare, and fairness.Comment: 12 page
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