Kaluza-Klein Dark Matter from Deconstructed Universal Extra Dimensions

We consider Kaluza-Klein dark matter from deconstructed or latticized universal extra dimensions and study in this model the positron flux from Kaluza-Klein dark matter annihilation in the galactic halo.Comment: 4 pages, 1 figure. To appear in Proceedings of SUSY06, the 14th International Conference on Supersymmetry and the Unification of Fundamental Interactions, UC Irvine, California, 12-17 June 200

Limitations of Quantum Coset States for Graph Isomorphism

It has been known for some time that graph isomorphism reduces to the hidden subgroup problem (HSP). What is more, most exponential speedups in quantum computation are obtained by solving instances of the HSP. A common feature of the resulting algorithms is the use of quantum coset states, which encode the hidden subgroup. An open question has been how hard it is to use these states to solve graph isomorphism. It was recently shown by Moore, Russell, and Schulman that only an exponentially small amount of information is available from one, or a pair of coset states. A potential source of power to exploit are entangled quantum measurements that act jointly on many states at once. We show that entangled quantum measurements on at least \Omega(n log n) coset states are necessary to get useful information for the case of graph isomorphism, matching an information theoretic upper bound. This may be viewed as a negative result because highly entangled measurements seem hard to implement in general. Our main theorem is very general and also rules out using joint measurements on few coset states for some other groups, such as GL(n, F_{p^m}) and G^n where G is finite and satisfies a suitable property.Comment: 25 page

Neutrino Oscillations in Deconstructed Dimensions

We present a model for neutrino oscillations in the presence of a deconstructed non-gravitational large extra dimension compactified on the boundary of a two-dimensional disk. In the deconstructed phase, sub-mm lattice spacings are generated from the hierarchy of energy scales between 1 TeV and the usual B-L breaking scale 10^{15} GeV. Here, short distance cutoffs down to 1 eV can be motivated by the strong coupling behavior of gravity in local discrete extra dimensions. This could make it possible to probe the discretization of extra dimensions and non-trivial field configurations in theory spaces which have only a few sites, i.e., for coarse latticizations. Thus, the model has relevance to present and future precision neutrino oscillation experiments.Comment: 38 pages, 11 figures, typos correcte

Classical Cryptographic Protocols in a Quantum World

Cryptographic protocols, such as protocols for secure function evaluation (SFE), have played a crucial role in the development of modern cryptography. The extensive theory of these protocols, however, deals almost exclusively with classical attackers. If we accept that quantum information processing is the most realistic model of physically feasible computation, then we must ask: what classical protocols remain secure against quantum attackers? Our main contribution is showing the existence of classical two-party protocols for the secure evaluation of any polynomial-time function under reasonable computational assumptions (for example, it suffices that the learning with errors problem be hard for quantum polynomial time). Our result shows that the basic two-party feasibility picture from classical cryptography remains unchanged in a quantum world.Comment: Full version of an old paper in Crypto'11. Invited to IJQI. This is authors' copy with different formattin

Districts and Data: Developing Capacity for Effective Data Use

The development of large and interconnected data sets has awakened educators to the value of strategically using data to inform education policy and improve instruction. Recognizing that using data effectively is critical to improving student achievement, numerous organizations and agencies, including the Bill & Melinda Gates Foundation, are supporting school districts and other education agencies in building their capacity to generate and use data. Even with essential data systems and supports in place, districts face challenges related to the strategic use of data. Many districts do not know what questions to ask, what data to use, or how to interpret findings to improve policy and practice. This brief discusses four key recommendations related to the strategic use of data and suggests ways districts can overcome challenges associated with these recommendations. Data and supporting examples in this brief are drawn from work conducted as part of the evaluation of strategic data use initiatives

The Teacher-Student Data Link Project: Three Lasting Accomplishments

In 2010, the Bill & Melinda Gates Foundation invited five states and three pilot districts in each state to participate in the Teacher-Student Data Link (TSDL) project. Mathematica developed a report presenting findings from 2011, the project's first year of implementation. Building on that report, this brief articulates three lasting accomplishments of the TSDL project: (1) Building implementation support for states and districts; (2) Continuing collaboration among states; and (3) Creating new TSDL-inspired activities. The brief also presents additional resources regarding the activities of the pilot states and districts, best practices for initiatives like TSDL that intend to bolster linked teacher-student data, and a support network for education agencies involved in similar work