Classification of the N=2, Z2 X Z2-symmetric type II orbifolds and their type II asymmetric duals

Using free world-sheet fermions, we construct and classify all the N=2, Z2 X Z2 four-dimensional orbifolds of the type IIA/B strings for which the orbifold projections act symmetrically on the left and right movers. We study the deformations of these models out of the fermionic point, deriving the partition functions at a generic point in the moduli of the internal torus T6=T2 X T2 X T2. We investigate some of their perturbative and non-perturbative dualities and construct new dual pairs of type IIA/type II asymmetric orbifolds, which are related non-perturbatively and allow us to gain insight into some of the non-perturbative properties of the type IIA/B strings in four dimensions. In particular, we consider some of the (non-)perturbative gravitational corrections.Comment: Latex, 47 pages, no figure

Renormalization effects on neutrino masses and mixing in a string-inspired SU(4) X SU(2)_L X SU(2)_R X U(1)_X model

We discuss renormalization effects on neutrino masses and mixing angles in a supersymmetric string-inspired SU(4) X SU(2)_L X SU(2)_R X U(1)_X model, with matter in fundamental and antisymmetric tensor representations and singlet Higgs fields charged under the anomalous U(1)_X family symmetry. The quark, lepton and neutrino Yukawa matrices are distinguished by different Clebsch-Gordan coefficients. The presence of a second U(1)_X breaking singlet with fractional charge allows a more realistic, hierarchical light neutrino mass spectrum with bi-large mixing. By numerical investigation we find a region in the model parameter space where the neutrino mass-squared differences and mixing angles at low energy are consistent with experimental data.Comment: 9 pages, 7 figures; references adde

CONTRACT LAW—BREWING A SOLUTION: AN ARGUMENT FOR FAIRNESS IN MASSACHUSETTS BEER FRANCHISE LAWS

For over a decade, Massachusetts craft brewers have been fighting to change the Massachusetts Beer Franchise Law as it directly impacts their success. The Law makes it extremely difficult for a brewer to escape a contract with a distributor. Once a brewer and a distributor establish a relationship for at least six months, a brewer must show good cause to terminate the agreement, which can be extremely time-consuming, cumbersome, and costly. There is no written or oral agreement requirement, and the statutory provision can take effect without the knowledge of either party. Thus, an up-and-coming brewery without knowledge of the statute may think it is just testing out the waters with a distribution company and can end up stuck working with that company indefinitely. The problems arise when a brewer is unhappy with a distributor and cannot do anything about it. The Massachusetts Beer Franchise Law is meant to protect small distributors from large breweries. The legislation did not take into account the negative effects that could arise if the industry dynamic were to change. Now, it is the small brewers that need protection from large distributors. This Note discusses the negative impacts of static statutory solutions and proposes new, dynamic statutory provisions to resolve the ongoing conflict created by the Massachusetts Beer Franchise Law. Additionally, this Note considers non-legislative protections such as contractual provisions a brewer might consider when entering into a distribution agreement

GPS network-based approach to mitigate residual tropospheric delay in low latitude areas

A strong spatio-temporal variation of the wet component in the troposphere leaves us in a peculiar predicament. The residual tropospheric delay will remain in the measurements and therefore affect the estimation of related parameters. In the areas of hot and wet climate conditions, especially in the equatorial or low latitude regions, the strong tropospheric effect on GPS measurements is unquestionable. This study proposes geometric modeling through the network-based approach to mitigate the residual tropospheric delay in such regions. A part of Southeast Asia is selected as a test area for the study, which covers Malaysia and Singapore. Tests are conducted in post-processing but in the “simulating RTK� mode, and evaluated by the number of ambiguity fixes and the accuracy of the coordinate results. Network-based RTK positioning in low latitude areas has shown that the proposed technique can enhance ambiguity resolution by pivoting the ionosphere-free measurements through the mitigated residual tropospheric delay

String Model Building on Quantum Annealers

For the first time the direct construction of string models on quantum annealers has been explored and has been investigated their efficiency and effectiveness in the model discovery process. Through a thorough comparison with traditional methods such as simulated annealing, random scans, and genetic algorithms, it is highlighted the potential advantages offered by quantum annealers, which in this study promised to be roughly 50 times faster than random scans and genetic algorithm and approximately four times faster than simulated annealing