Quantum Effective Action in Spacetimes with Branes and Boundaries

We construct quantum effective action in spacetime with branes/boundaries. This construction is based on the reduction of the underlying Neumann type boundary value problem for the propagator of the theory to that of the much more manageable Dirichlet problem. In its turn, this reduction follows from the recently suggested Neumann-Dirichlet duality which we extend beyond the tree level approximation. In the one-loop approximation this duality suggests that the functional determinant of the differential operator subject to Neumann boundary conditions in the bulk factorizes into the product of its Dirichlet counterpart and the functional determinant of a special operator on the brane -- the inverse of the brane-to-brane propagator. As a byproduct of this relation we suggest a new method for surface terms of the heat kernel expansion. This method allows one to circumvent well-known difficulties in heat kernel theory on manifolds with boundaries for a wide class of generalized Neumann boundary conditions. In particular, we easily recover several lowest order surface terms in the case of Robin and oblique boundary conditions. We briefly discuss multi-loop applications of the suggested Dirichlet reduction and the prospects of constructing the universal background field method for systems with branes/boundaries, analogous to the Schwinger-DeWitt technique.Comment: LaTeX, 25 pages, final version, to appear in Phys. Rev.

Steeped in Rhetoric: Digital Populism and the Tea Party Movement

Though politically disparate and hard to quantify, one of the binding elements of the Tea Party Movement is Internet Communication Technology, or new media. Social media, online discussion boards, blogs, and other forms of new media constitute a veritable component of the discourse among its members. From the whispering confederation of conservative bloggers in its beginning stages, to the relatively quick transition into a social media powerhouse, the Tea Party fits into the category of dissident social movements in a new way than movements past, in that web-based communication is a staple of the movement. Also, the Tea Party's "Web 2.0" identity intersects with a tradition of populism, combining new media communication with rhetoric depicting the Tea Party as "common" people pitted against "elitist" enemies of the country. The populist sentiments within the Tea Party reflect a wider understanding about the role of technology in fostering democracy, and "restoring" the republic back to its "core values." Tea Partiers, then, could be described as "Digital Populists," historically situated among the histories of other American populist moments, but understanding new media technology as a new way to shape political discourse. Throughout this project, then, my aim is to link populist rhetoric with technological determinism, using the Tea Party's new media ecology as a case study. The first chapter provides historical examples of populist rhetorical frameworks informing the relationship between technology and society; Chapter 2 is a case study of three Tea Party websites; and Chapter 3 is a theoretical reflection on the data that analyzes how the Tea Party's engagement with new media fits into broader conversations about technology and democracy. At the core of this project is an inquiry into how technology works in our everyday lives. My analysis questions the presumption that new media communication technology fosters a more democratic society. Specifically, I argue that, while steeped in rhetoric of technological liberation, revolution, and democracy, the Tea Party's approach to new media contributes less to a vibrant culture of democratic engagement, and more to a peculiar and unstable technological mythology in American culture

Higher Spin Gravitational Couplings and the Yang--Mills Detour Complex

Gravitational interactions of higher spin fields are generically plagued by inconsistencies. We present a simple framework that couples higher spins to a broad class of gravitational backgrounds (including Ricci flat and Einstein) consistently at the classical level. The model is the simplest example of a Yang--Mills detour complex, which recently has been applied in the mathematical setting of conformal geometry. An analysis of asymptotic scattering states about the trivial field theory vacuum in the simplest version of the theory yields a rich spectrum marred by negative norm excitations. The result is a theory of a physical massless graviton, scalar field, and massive vector along with a degenerate pair of zero norm photon excitations. Coherent states of the unstable sector of the model do have positive norms, but their evolution is no longer unitary and their amplitudes grow with time. The model is of considerable interest for braneworld scenarios and ghost condensation models, and invariant theory.Comment: 19 pages LaTe

Further functional determinants

Functional determinants for the scalar Laplacian on spherical caps and slices, flat balls, shells and generalised cylinders are evaluated in two, three and four dimensions using conformal techniques. Both Dirichlet and Robin boundary conditions are allowed for. Some effects of non-smooth boundaries are discussed; in particular the 3-hemiball and the 3-hemishell are considered. The edge and vertex contributions to the $C_{3/2}$ coefficient are examined.Comment: 25 p,JyTex,5 figs. on request

Effective action and heat kernel in a toy model of brane-induced gravity

We apply a recently suggested technique of the Neumann-Dirichlet reduction to a toy model of brane-induced gravity for the calculation of its quantum one-loop effective action. This model is represented by a massive scalar field in the $(d+1)$-dimensional flat bulk supplied with the $d$-dimensional kinetic term localized on a flat brane and mimicking the brane Einstein term of the Dvali-Gabadadze-Porrati (DGP) model. We obtain the inverse mass expansion of the effective action and its ultraviolet divergences which turn out to be non-vanishing for both even and odd spacetime dimensionality $d$. For the massless case, which corresponds to a limit of the toy DGP model, we obtain the Coleman-Weinberg type effective potential of the system. We also obtain the proper time expansion of the heat kernel in this model associated with the generalized Neumann boundary conditions containing second order tangential derivatives. We show that in addition to the usual integer and half-integer powers of the proper time this expansion exhibits, depending on the dimension $d$, either logarithmic terms or powers multiple of one quarter. This property is considered in the context of strong ellipticity of the boundary value problem, which can be violated when the Euclidean action of the theory is not positive definite.Comment: LaTeX, 20 pages, new references added, typos correcte

End-to-End Localization and Ranking for Relative Attributes

We propose an end-to-end deep convolutional network to simultaneously localize and rank relative visual attributes, given only weakly-supervised pairwise image comparisons. Unlike previous methods, our network jointly learns the attribute's features, localization, and ranker. The localization module of our network discovers the most informative image region for the attribute, which is then used by the ranking module to learn a ranking model of the attribute. Our end-to-end framework also significantly speeds up processing and is much faster than previous methods. We show state-of-the-art ranking results on various relative attribute datasets, and our qualitative localization results clearly demonstrate our network's ability to learn meaningful image patches.Comment: Appears in European Conference on Computer Vision (ECCV), 201

Engineering Education for High-Ability Students

Over the course of their careers, engineers command a breadth and depth of knowledge from science, mathematics, society, politics, and economics that is needed for continuously updating their knowledge of the latest discoveries and advances. Driven by curiosity and enabled by rapid information technology, engineers are kept abreast of the latest advancements almost instantaneously. Today’s scientific knowledge is fluid and complex, yet these traits of engineering remain constant: the ability to define structure, plan, repeatedly evaluate, and align results to the initial objective. Engineering teachers need to facilitate their students’ ability to access information effectively and to apply it appropriately, as well as to foster a strong foundation in science and mathematics. Skill development in creativity, communication, and business acumen is the hallmark of an effective engineering education program and curriculum

Reasoned action approach to analyze differences in athletes\u27 physical activity during COVID-19

The purpose of this study was to examine the reasoned action approach (RAA) in relation to the impact of COVID-19 on college athletes’ physical activity (PA). Participants were college athletes (ages 18-22 years) who were involved in university, club, and/or intramural sport. The RAA constructs were measured for the three different types of PA behaviors. Statistical analyses included ANOVA and multiple regression analyses to evaluate the RAA determinants of PA intentions. Results partially supported theoretical expectations. All RAA constructs had an impact on perceived norms indicating a dominant influence. Remote social interaction/training during isolation periods are suggested to promote sustained conditioning among college athletes

Diffeomorphism invariant eigenvalue problem for metric perturbations in a bounded region

We suggest a method of construction of general diffeomorphism invariant boundary conditions for metric fluctuations. The case of $d+1$ dimensional Euclidean disk is studied in detail. The eigenvalue problem for the Laplace operator on metric perturbations is reduced to that on $d$-dimensional vector, tensor and scalar fields. Explicit form of the eigenfunctions of the Laplace operator is derived. We also study restrictions on boundary conditions which are imposed by hermiticity of the Laplace operator.Comment: LATeX file, no figures, no special macro

Heat Kernel Expansion for Semitransparent Boundaries

We study the heat kernel for an operator of Laplace type with a $\delta$-function potential concentrated on a closed surface. We derive the general form of the small $t$ asymptotics and calculate explicitly several first heat kernel coefficients.Comment: 16 page