Lattice supersymmetry

A method is proposed for latticizing a class of supersymmetric gauge theories, including N=4 super Yang-Mills. The technique is inspired by recent work on ``deconstruction''. Part of the target theory's supersymmetry is realized exactly on the lattice, reducing or eliminating the need for fine tuning. (Talk based on the paper "Supersymmetry on a Spatial Lattice", hep-lat/0206019, by D.B.K., Emmanuel Katz and Mithat Unsal).Comment: Lattice2002(higgssusy), 3 pages, no figure

W physics at the ILC with polarized beams as a probe of the Littlest Higgs Model

We study the possibility of using W pair production and leptonic decay of one of the W's at the ILC with polarized beams as a probe of the Littlest Higgs Model. We consider cross-sections, polarization fractions of the W's, leptonic decay energy and angular distributions, and left-right polarization asymmetry as probes of the model. With parameter values allowed by present experimental constraints detectable effects on these observables at typical ILC energies of 500 GeV and 800 GeV will be present. Beam polarization is further found to enhance the sensitivity.Comment: 17 pages, plain latex, 6 figures, replaced with version accepted by JHEP, typographical errors removed, notation and references improved, new references added, explanation added in appendix regarding beam polarization dependenc

Quantum Gravity at the Planck Length

I describe our understanding of physics near the Planck length, in particular the great progress in the last four years in string theory. These are lectures presented at the 1998 SLAC Summer Institute.Comment: 33 pages, LaTeX, 11 epsf figure

The Long Range Gravitational Potential Energy Between Strings

We calculate the gravitational potential energy between infinitely long parallel strings with tensions \tau_1 and \tau_2. Classically, it vanishes, but at one loop, we find that the long range gravitational potential energy per unit length is U/L = 24G_N^2\tau_1\tau_2/(5 \pi a^2) + ..., where a is the separation between the strings, G_N is Newton's constant, and we set \hbar = c =1. The ellipses represent terms suppressed by more powers of G_N \tau_i. Typically, massless bulk fields give rise at one loop to a long range potential between p-branes in space-times of dimension p+2+1. The contribution to this potential from bulk scalars is computed for arbitrary p (strings correspond to p=1) and in the case of three-branes its possible relevance for cosmological quintessence is commented on.Comment: 10 pages, 6 figure

Attributes of Big Data Analytics for Data-Driven Decision Making in Cyber-Physical Power Systems

Big data analytics is a virtually new term in power system terminology. This concept delves into the way a massive volume of data is acquired, processed, analyzed to extract insight from available data. In particular, big data analytics alludes to applications of artificial intelligence, machine learning techniques, data mining techniques, time-series forecasting methods. Decision-makers in power systems have been long plagued by incapability and weakness of classical methods in dealing with large-scale real practical cases due to the existence of thousands or millions of variables, being time-consuming, the requirement of a high computation burden, divergence of results, unjustifiable errors, and poor accuracy of the model. Big data analytics is an ongoing topic, which pinpoints how to extract insights from these large data sets. The extant article has enumerated the applications of big data analytics in future power systems through several layers from grid-scale to local-scale. Big data analytics has many applications in the areas of smart grid implementation, electricity markets, execution of collaborative operation schemes, enhancement of microgrid operation autonomy, management of electric vehicle operations in smart grids, active distribution network control, district hub system management, multi-agent energy systems, electricity theft detection, stability and security assessment by PMUs, and better exploitation of renewable energy sources. The employment of big data analytics entails some prerequisites, such as the proliferation of IoT-enabled devices, easily-accessible cloud space, blockchain, etc. This paper has comprehensively conducted an extensive review of the applications of big data analytics along with the prevailing challenges and solutions

Horava-Lifshitz Cosmology: A Review

This article reviews basic construction and cosmological implications of a power-counting renormalizable theory of gravitation recently proposed by Horava. We explain that (i) at low energy this theory does not exactly recover general relativity but instead mimic general relativity plus dark matter; that (ii) higher spatial curvature terms allow bouncing and cyclic universes as regular solutions; and that (iii) the anisotropic scaling with the dynamical critical exponent z=3 solves the horizon problem and leads to scale-invariant cosmological perturbations even without inflation. We also comment on issues related to an extra scalar degree of freedom called scalar graviton. In particular, for spherically-symmetric, static, vacuum configurations we prove non-perturbative continuity of the lambda->1+0 limit, where lambda is a parameter in the kinetic action and general relativity has the value lambda=1. We also derive the condition under which linear instability of the scalar graviton does not show up.Comment: 28 pages, invited review for CQG; version to be published (v2

Female Faculty Perspectives On Blended Learning At Universities In Saudi Arabia

Adopting technology is one of the priorities in the Saudi education system. The reform of Saudi education leads to the need to focus on BL as a tool for adopting technology into any college classroom. This study focuses specifically on technology usage for teaching among female faculty. In 2018, women’s education in Saudi Arabia has undergone an incredible social transition, and women’s education is different and more advanced than before. This study looks to learn about female faculty members’ views and experiences as they relate to the adoption of BL in their classrooms. It seeks to provide in-depth knowledge essential to adopt BL according to a Diffusion of Innovation (DOI) and Technology Acceptance Model (TAM) theoretical framework. DOI explains adoption in the social setting with all the possible social culture factors. The TAM explains faculty level acceptance, specifically explaining external factors’ effects on faculty members’ beliefs and influencing them toward the BL. Because this study gathers information on female faculty members’ experiences with BL, a qualitative theme analysis was the appropriate research design to use. In particular, I used a qualitative research method to study female faculty members’ perspectives, collecting data via individual interviews. It is included interviews with female faculty members from four public, 4-year institutions in Saudi Arabia. Faculty members’ flexibility and their relationship to the adoption of BL depended on their benefits and challenges. According to this study’s participants, the challenges of the BL approach in Saudi Arabia necessitate urgent strategic plans at all levels. Faculty members’ knowledge and understanding regarding the definitions of BL showed their acceptance. Faculty support should be a priority for these institutions, which should adopt policies to help achieve Vision 2030—a natural, well-organized way to reform higher education. The gender aspect of the teaching culture considerably impacts the female faculty’s use of BL in Saudi Arabia. This study’s results—that the women faculty believe there is a need for evaluation, and official leadership rules for the adoption of BL. To summarize, the results indicated that women adopted BL when circumstances permitted. The obstacles, in their eyes, were a lack of faculty support, poor strategic evaluation plans, and insufficient empowerment at the institutional level

Mercury anomalies associated with three extinction events (Capitanian Crisis, Latest Permian Extinction and the Smithian/Spathian Extinction) in NW Pangea

Copyright © Cambridge University Press 2015. Strata of Permian - Early Triassic age that include a record of three major extinction events (Capitanian Crisis, Latest Permian Extinction and the Smithian/Spathian Extinction) were examined at the Festningen section, Spitsbergen. Over the c. 12 Ma record examined, mercury in the sediments shows relatively constant background values of 0.005-0.010 μg g -1 . However, there are notable spikes in Hg concentration over an order of magnitude above background associated with the three extinctions. The Hg/total organic carbon (TOC) ratio shows similar large spikes, indicating that they represent a true increase in Hg loading to the environment. We argue that these represent Hg loading events associated with enhanced Hg emissions from large igneous province (LIP) events that are synchronous with the extinctions. The Hg anomalies are consistent across the NW margin of Pangea, indicating that widespread mercury loading occurred. While this provides utility as a chemostratigraphic marker the Hg spikes may also indicate loading of toxic metals to the environment, a contributing cause to the mass extinction events

Boundary Contributions Using Fermion Pair Deformation

Continuing the study of boundary BCFW recursion relation of tree level amplitudes initiated in \cite{Feng:2009ei}, we consider boundary contributions coming from fermion pair deformation. We present the general strategy for these boundary contributions and demonstrate calculations using two examples, i.e, the standard QCD and deformed QCD with anomalous magnetic momentum coupling. As a by-product, we have extended BCFW recursion relation to off-shell gluon current, where because off-shell gluon current is not gauge invariant, a new feature must be cooperated.Comment: 26 pages, 4 figure

Trace anomalies and chiral Ward identities

In a simple abelian spinor field theory, the canonical trace identities for certain axial-vector and axial-scalar operators are reexamined in dimensional regularization, some disagreements with previous results are found and an interesting new phenomenon is observed and briefly discussed.Comment: 4 pages, no figure, typos remove