Physics

Using the Eguchi-Kawai equivalence, we provide regularizations of supersymmetric quiver and Chern-Simons gauge theories which leave the supersymmetries unbroken. This allow us to study many interesting theories on a computer. As examples we construct large-N reduced models of supersymmetric QCD with flavor and the ABJM model of multiple M2 branes.

We consider a supersymmetric matrix quantum mechanics. This is obtained by adding Myers and mass terms to the dimensional reduction of 4d N = 1 super Yang-Mills theory to one dimension. Using this model we construct 4d N = 1 super Yang-Mills theory in the planar limit by using the Eguchi-Kawai equivalence. This regularization turns out to be free from the sign problem at the regularized level. The same matrix quantum mechanics is also used to provide a nonperturbative formulation of 4d N = 1 super Yang-Mills theory on a noncommutative space.

A simple covariant formalism to describe flavor and CP violation in the left-handed quark sector in a model independent way is provided. The introduction of a covariant basis, which makes the standard model approximate symmetry structure manifest, leads to a physical and transparent picture of flavor conversion processes. Our method is particularly useful to derive robust bounds on models with arbitrary mechanisms of alignment. Known constraints on flavor violation in the K and D systems are reproduced in a straightforward manner. Assumptions-free limits, based on top flavor violation at the LHC, are then obtained. In the absence of signal, with 100 fb−1 of data, the LHC will exclude weakly coupled (strongly coupled) new physics up to a scale of 0.6 TeV (7.6 TeV), while at present no general constraint can be set related to Δt= 1 processes. LHC data will constrain ΔF= 2 contributions via same-sign tops signal, with a model independent exclusion region of 0.08 TeV (1.0 TeV). However, in this case, stronger bounds are found from the study of CP violation in $ D - \overline D $ mixing with a scale of 0.57 TeV (7.2 TeV). In addition, we apply our analysis to models of supersymmetry and warped extra dimension. The minimal flavor violation framework is also discussed, where the formalism allows to distinguish between the linear and generic non-linear limits within this class of models.

A simple formalism to describe flavor and CP violation in a model independent way is provided. Our method is particularly useful to derive robust bounds on models with arbitrary mechanisms of alignment. Known constraints on flavor violation in the K and D systems are reproduced in a straightforward and covariant manner. Assumptions-free limits, based on top flavor violation at the LHC, are then obtained. In the absence of signal, with 100 fb −1 of data, the LHC will exclude weakly coupled (strongly coupled) new physics up to a scale of 0.6 TeV (7.6 TeV), while at present no general constraint can be set related to ∆t = 1 processes. ∆F = 2 contributions will be constrained via same-sign tops signal, with a model independent exclusion region of 0.08 TeV (1.0 TeV). However, in this case, stronger bounds are found from the study of CP violation in D − D mixing with a scale of 0.57 TeV (7.2 TeV). We also apply our analysis to supersymmetric and warped extra dimension models.

I put metastable supersymmetry breaking in a cosmological context. I argue that under reasonable assumptions, the cooling down early Universe favors metastable SUSY-breaking vacua over the stable supersymmetric vacua. To illustrate the general argument, I analyze the early-Universe history of the Intriligator-Seiberg-Shih model.

I put metastable supersymmetry breaking in a cosmological context. I argue that under reasonable assumptions, the cooling down early Universe favors metastable SUSY-breaking vacua over the stable supersymmetric vacua. To illustrate the general argument, I analyze the early-Universe history of the Intriligator-Seiberg-Shih model.

We analyze the renormalization properties of quantum field theories in de Sitter space and show that only two of the maximally invariant vacuum states of free fields lead to consistent perturbation expansions. One is the Euclidean vacuum and the other can be viewed as an analytic continuation of Euclidean functional integrals on RP d . The corresponding Lorentzian manifold is the future half of global de Sitter space with boundary conditions on fields at the origin of time. We argue that the perturbation series in this case has divergences at the origin which render the future evolution of the system indeterminate, without a better understanding of high energy physics.

dS/CFT gives a perturbatively gauge invariant definition of particle masses in de Sitter (dS) space. We show, in a toy model in which the graviton is replaced with a minimally coupled massless scalar field, that loop corrections to these masses are infrared (IR) divergent. We argue that this implies anomalous dependence of masses on the cosmological constant, in a true theory of quantum gravity. This is in accord with the hypothesis of Cosmological SUSY Breaking (CSB).

We present a complete quantum mechanical description of a flat FRW universe with equation of state p = ρ. We find a detailed correspondence with our heuristic picture of such a universe as a dense black hole fluid. Features of the geometry are derived from purely quantum input.

We study the planar-flow distributions of narrow, highly boosted, massive QCD jets. Using the factorization properties of QCD in the collinear limit, we compute the planar-flow jet function from the one-to-three splitting function at tree-level. We derive the leading-log behavior of the jet function analytically. We also compare our semi-analytic jet function with parton-shower predictions using various generators.

We consider a supersymmetric matrix quantum mechanics. This is obtained by adding Myers and mass terms to the dimensional reduction of 4d N = 1 super Yang-Mills theory to one dimension. Using this model we construct 4d N = 1 super Yang-Mills theory in the planar limit by using the Eguchi-Kawai equivalence. This regularization turns out to be free from the sign problem at the regularized level. The same matrix quantum mechanics is also used to provide a nonperturbative formulation of 4d N = 1 super Yang-Mills theory on a noncommutative space.

dS/CFT gives a perturbatively gauge invariant definition of particle masses in de Sitter (dS) space. We show, in a toy model in which the graviton is replaced with a minimally coupled massless scalar field, that loop corrections to these masses are infrared (IR) divergent. We argue that this implies anomalous dependence of masses on the cosmological constant, in a true theory of quantum gravity. This is in accord with the hypothesis of Cosmological SUSY Breaking (CSB).

We present a complete quantum mechanical description of a flat FRW universe with equation of state p = ρ. We find a detailed correspondence with our heuristic picture of such a universe as a dense black hole fluid. Features of the geometry are derived from purely quantum input.

A flat panel, compact virtual image projection display is presented. It is based on a light-guided optical configuration that includes three linear holographic gratings recorded on one planar transparent substrate so as to obtain a magnified virtual image for a small input display. The principles of the projection display, unique design, and procedures for experimentally recording an actual planar configuration are presented, along with evaluation results. The results reveal that a field of view of Ϯ8°can be readily achieved at a distance of 36 cm, making such planar configurations attractive for head-up displays.

Closed form analytical solutions of diffraction efficiency for transmission surface relief gratings in the resonance domain are presented. These are obtained by modeling the surface relief gratings with equivalent graded index gratings having Bragg properties, so as to allow for an optimum choice of grating parameters that would lead to high diffraction efficiencies. The calculated and experimental results reveal that the diffraction efficiency can be greater than 85% with optimized grating parameters within their certain strict limits. Ó 2004 Elsevier B.V. All rights reserved. PACS: 42.40.Lx.; 42.25.Fx.; 42.40.Eq.; 42.79.Dj