1,418 research outputs found
GENDER'S ROLE IN MANUSCRIPT ACCEPTANCE: SEX IN THE JOURNAL
Women authors fare poorly at the hands of referees in some economics journals, especially when the review process is not blind. Using data on the 155 manuscripts submitted to the NJARE for publication during the period 1984-88, we found no evidence of differential referee acceptance rates for manuscripts with female and male lead authors.Teaching/Communication/Extension/Profession,
Multi-Party Pseudo-Telepathy
Quantum entanglement, perhaps the most non-classical manifestation of quantum
information theory, cannot be used to transmit information between remote
parties. Yet, it can be used to reduce the amount of communication required to
process a variety of distributed computational tasks. We speak of
pseudo-telepathy when quantum entanglement serves to eliminate the classical
need to communicate. In earlier examples of pseudo-telepathy, classical
protocols could succeed with high probability unless the inputs were very
large. Here we present a simple multi-party distributed problem for which the
inputs and outputs consist of a single bit per player, and we present a perfect
quantum protocol for it. We prove that no classical protocol can succeed with a
probability that differs from 1/2 by more than a fraction that is exponentially
small in the number of players. This could be used to circumvent the detection
loophole in experimental tests of nonlocality.Comment: 11 pages. To be appear in WADS 2003 proceeding
Improved Quantum Communication Complexity Bounds for Disjointness and Equality
We prove new bounds on the quantum communication complexity of the
disjointness and equality problems. For the case of exact and non-deterministic
protocols we show that these complexities are all equal to n+1, the previous
best lower bound being n/2. We show this by improving a general bound for
non-deterministic protocols of de Wolf. We also give an O(sqrt{n}c^{log^*
n})-qubit bounded-error protocol for disjointness, modifying and improving the
earlier O(sqrt{n}log n) protocol of Buhrman, Cleve, and Wigderson, and prove an
Omega(sqrt{n}) lower bound for a large class of protocols that includes the
BCW-protocol as well as our new protocol.Comment: 11 pages LaTe
On Quantum Algorithms
Quantum computers use the quantum interference of different computational
paths to enhance correct outcomes and suppress erroneous outcomes of
computations. In effect, they follow the same logical paradigm as
(multi-particle) interferometers. We show how most known quantum algorithms,
including quantum algorithms for factorising and counting, may be cast in this
manner. Quantum searching is described as inducing a desired relative phase
between two eigenvectors to yield constructive interference on the sought
elements and destructive interference on the remaining terms.Comment: 15 pages, 8 figure
Efficient discrete-time simulations of continuous-time quantum query algorithms
The continuous-time query model is a variant of the discrete query model in
which queries can be interleaved with known operations (called "driving
operations") continuously in time. Interesting algorithms have been discovered
in this model, such as an algorithm for evaluating nand trees more efficiently
than any classical algorithm. Subsequent work has shown that there also exists
an efficient algorithm for nand trees in the discrete query model; however,
there is no efficient conversion known for continuous-time query algorithms for
arbitrary problems.
We show that any quantum algorithm in the continuous-time query model whose
total query time is T can be simulated by a quantum algorithm in the discrete
query model that makes O[T log(T) / log(log(T))] queries. This is the first
upper bound that is independent of the driving operations (i.e., it holds even
if the norm of the driving Hamiltonian is very large). A corollary is that any
lower bound of T queries for a problem in the discrete-time query model
immediately carries over to a lower bound of \Omega[T log(log(T))/log (T)] in
the continuous-time query model.Comment: 12 pages, 6 fig
CHOOSING ALTERNATIVES TO CONTAMINATED GROUND WATER SUPPLIES: A SEQUENTIAL DECISION FRAMEWORK UNDER UNCERTAINTY
In increasing numbers, communities that rely on groundwater for drinking supplies have discovered contamination from agricultural pesticides and herbicides, road salt, underground fuel storage, and septic systems. A variety of short- and long-run remedies are available with highly uncertain outcomes. An appropriate technique for solving a benefit-cost problem of this type is a sequential decision framework using stochastic dynamic programming procedures for solution. The approach is illustrated here by means of an application to the problem of the recent contamination of the groundwater of Whately, Massachusetts by the agricultural fumigant EDB and the pesticide aldicarb.Environmental Economics and Policy,
Exact quantum query complexity of
In the exact quantum query model a successful algorithm must always output
the correct function value. We investigate the function that is true if exactly
or of the input bits given by an oracle are 1. We find an optimal
algorithm (for some cases), and a nontrivial general lower and upper bound on
the minimum number of queries to the black box.Comment: 19 pages, fixed some typos and constraint
Causality and Cirel'son bounds
An EPR-Bell type experiment carried out on an entangled quantum system can
produce correlations stronger than allowed by local realistic theories. However
there are correlations that are no-signaling and are more non local than the
quantum correlations. Here we show that any correlations more non local than
those achievable in an EPR-Bell type experiment necessarily allow -in the
context of the quantum formalism- both for signaling and for generation of
entanglement. We use our approach to rederive Cirel'son bound for the CHSH
expression, and we derive a new Cirel'son type bound for qutrits. We discuss in
detail the interpretation of our approach.Comment: 5 page
Tsirelson's bound and supersymmetric entangled states
A superqubit, belonging to a -dimensional super-Hilbert space,
constitutes the minimal supersymmetric extension of the conventional qubit. In
order to see whether superqubits are more nonlocal than ordinary qubits, we
construct a class of two-superqubit entangled states as a nonlocal resource in
the CHSH game. Since super Hilbert space amplitudes are Grassmann numbers, the
result depends on how we extract real probabilities and we examine three
choices of map: (1) DeWitt (2) Trigonometric (3) Modified Rogers. In cases (1)
and (2) the winning probability reaches the Tsirelson bound
of standard quantum mechanics. Case (3)
crosses Tsirelson's bound with . Although all states used
in the game involve probabilities lying between 0 and 1, case (3) permits other
changes of basis inducing negative transition probabilities.Comment: Updated to match published version. Minor modifications. References
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