Solar Energy and Cities: A Solution To Environmental Degradation - A Case Study of the Emergence of Solar Energy in San Jose, California; San Antonio, Texas; and Honolulu, Hawaii

Senior Project submitted to The Division of Social Studies of Bard College

Lifting Slepton Masses with a Non-universal, Non-anomalous U(1)'_{NAF} in Anomaly Mediated SUSY breaking

We extend the Minimum Supersymmetry Standard Model by a non-anomalous family (NAF) U(1)'_{NAF} gauge symmetry. All gauge anomalies are cancelled with no additional exotics other than the three right-handed neutrinos. The FI D-terms associated with the U(1)'_{NAF} symmetry lead to additional positive contributions to slepton squared masses. In a RG invariant way, this thus solves the tachyonic slepton mass problem in Anomaly Mediated Supersymmetry Breaking. In addition, the U (1)'_{NAF} symmetry naturally gives rise to the fermion mass hierarchy and mixing angles, and determines the mass spectrum of the sparticles.Comment: 13 pages; v2: version to appear in Phys. Lett.

TeV-Scale Horizontal Symmetry and the Slepton Mass Problem of Anomaly Mediation

We propose a new scenario for solving the tachyonic slepton mass problem of anomaly mediated supersymmetry breaking models with a non-Abelian horizontal gauge symmetry broken at the TeV scale. A specific model based on SU(3)_{H} horizontal symmetry is presented wherein the sleptons receive positive mass-squared from the asymptotically free SU(3)_{H} gauge sector. Approximate global symmetries present in the model strongly suppress flavor changing processes induced by the horizontal vector gauge bosons. The model predicts m_{h} < 120 GeV for the lightest Higgs boson mass, tan{beta} nearly equal to 4, and M_V = 1-4 TeV for the SU(3)_{H} gauge boson masses. The lightest SUSY particle is found to be the neutral Wino, which is a candidate for cold dark matter.Comment: 25 pages in LaTeX, 2 eps figure

A Unified Approach to Supersymmetry Breaking

General formulae for the soft SUSY breaking terms, valid in any SUGRA context, were derived in the mid-nineties. Since SUSY is not expected to have quantum anomalies, they should be valid in the quantum theory and be RG invariant down to the soft SUSY breaking scale. This observation enables us to give a uniform treatment of all phenomenological models for SUSY breaking and transmission, such as AMSB, GMSB, etc. In particular we find that the much discussed RG invariant formulae for soft SUSY breaking parameters in AMSB, effectively depend on a strong assumption of factorizability of the matter Kaehler metric. We then argue that there is no necessity for having ad hoc constructions such as mAMSB to counteract the negative squared slepton mass problem, since the natural framework that emerges in a sequestered model is one in which gaugino masses are as in AMSB, and the other soft terms are generated by RG running as in gaugino mediation.Comment: 13 page

Cannabigerol causes a CB1 receptor-dependent reduction in food consumption and weight gain

Slides describing work leading up to a professional scientific poster, created and presented at psych fest depicting my last two years of work in Dr. Kaplan\u27s BNS lab. I included a reflection paper discussing my time at Western

Active control of mid-wavelength infrared non-linearity in silicon photonic crystal slab

Natural materials’ inherently weak nonlinear response demands the design of artificial substitutes to avoid optically large samples and complex phase-matching techniques. Silicon photonic crystals are promising artificial materials for this quest. Their nonlinear properties can be modulated optically, paving the way for applications ranging from ultrafast information processing to quantum technologies. A two-dimensional 15-μm-thick silicon photonic structure, comprising a hexagonal array of air holes traversing the slab’s thickness, has been designed to support a guided resonance for the light with a wavelength of 4-μm. At the resonance conditions, a transverse mode of the light is strongly confined between the holes in the "veins" of the silicon component. Owing to the confinement, the structure exhibits a ratio of nonlinear to linear absorption coefficients threefold higher than the uniform silicon slab of the same thickness. A customised time-resolved Z-scan method with provisions to accommodate ultrafast pump-probe measurements was used to investigate and quantify the non-linear response. We show that optically pumping free charge carriers into the structure decouples the incoming light from the resonance and reduces the non-linear response. The time-resolved measurements suggest that the decoupling is a relatively long-lived effect on the scale comparable to the non-radiative recombination in the bulk material. Moreover, we demonstrate that the excited free carriers are not the source of the nonlinearity, as this property is determined by the structure design

Localized Supersoft Supersymmetry Breaking

We consider supersymmetry breaking models in which the MSSM is extended to include an additional chiral adjoint field for each gauge group with which the the MSSM gauginos acquire Dirac masses. We investigate a framework in which the Standard Model gauge fields propagate in the bulk of a warped extra dimension while quarks and leptons are localized on the ultraviolet brane. The adjoint fields are localized on the infrared brane, where supersymmetry is broken in a hidden sector. This setup naturally suppresses potentially large flavor violating effects, while allowing perturbative gauge coupling unification under SU(5) to be realized. The Standard Model superpartner masses exhibit a supersoft spectrum. Since the soft scalar masses are generated at very low scales of order the gaugino masses these models are significantly less fine-tuned than other supersymmetric models. The LSP in this class of models is the gravitino, while the NLSP is the stau. We show that this theory has an approximate R symmetry under which the gauginos are charged. This symmetry allows several possibilities for experimentally distinguishing the Dirac nature of the gauginos.Comment: 23 pages, 2 figure

Interference Effects between Three Coupled Bose-Einstein Condensates

We study the interference effects between three weakly linked trapped Bose-Einstein condensates (BEC) as a generalization of the two-component condensates. Three coupled Gross-Pitaevskii equations (GPE) are used to describe the dynamics of the system. The nonsinusoidal oscillation is found as a generalization of the Josephson effect in superconductivity. The self-trapped effects are also predicted in three coupled BEC. Moreover, in general case, the phase diagrams of the system are closed only for some special parameters, which can be used to determine the interaction parameters between atoms in BEC.Comment: 4 figure