Wave interactions in localizing media - a coin with many faces

A variety of heterogeneous potentials are capable of localizing linear non-interacting waves. In this work, we review different examples of heterogeneous localizing potentials which were realized in experiments. We then discuss the impact of nonlinearity induced by wave interactions, in particular its destructive effect on the localizing properties of the heterogeneous potentials.Comment: Review submitted to Intl. Journal of Bifurcation and Chaos Special Issue edited by G. Nicolis, M. Robnik, V. Rothos and Ch. Skokos 21 Pages, 8 Figure

Coupled symplectic maps as models for subdiffusive processes in disordered Hamiltonian lattices

© 2015 IMACS We investigate dynamically and statistically diffusive motion in a chain of linearly coupled 2-dimensional symplectic McMillan maps and find evidence of subdiffusion in weakly and strongly chaotic regimes when all maps of the chain possess a saddle point at the origin and the central map is initially excited. In the case of weak coupling, there is either absence of diffusion or subdiffusion with q > 1-Gaussian probability distributions, characterizing weak chaos. However, for large enough coupling and already moderate number of maps, the system exhibits strongly chaotic (q≈1) subdiffusive behavior, reminiscent of the subdiffusive energy spreading observed in a disordered Klein–Gordon Hamiltonian. Our results provide evidence that coupled symplectic maps can exhibit physical properties similar to those of disordered Hamiltonian systems, even though the local dynamics in the two cases is significantly different

Tailoring Optical Complex Fields with Nano-Metallic Surfaces

Recently there is an increasing interest in complex optical fields with spatially inhomogeneous state of polarizations and optical singularities. Novel effects and phenomena have been predicted and observed for light beams with these unconventional states. Nanostructured metallic thin film offers unique opportunities to generate, manipulate and detect these novel fields. Strong interactions between nano-metallic surfaces and complex optical fields enable the development of highly compact and versatile functional devices and systems. In this review, we first briefly summarize the recent developments in complex optical fields. Various nano-metallic surface designs that can produce and manipulate complex optical fields with tailored characteristics in the optical far field will be presented. Nano-metallic surfaces are also proven to be very effective for receiving and detection of complex optical fields in the near field. Advances made in this nascent field may enable the design of novel photonic devices and systems for a variety of applications such as quantum optical information processing and integrated photonic circuits

Getting farming on the agenda: Planning, policymaking, and governance practices of urban agriculture in New York City

How and why is urban agriculture taken up into local food policies and sustainability plans? This paper uses a case study of urban agriculture policymaking in New York City from 2007 to 2011 to examine the power-laden operation of urban environmental governance. It explores several ‘faces of power,’ including overt authority, institutionalized ‘rules of the game,’ and hegemony. It also investigates how multiple actors interact in policymaking processes, including through the construction and use of broad discursive concepts. Findings draw upon analysis of policy documents and semi-structured interviews with 43 subjects engaged in food systems policymaking. Some municipal decision-makers questioned the significance of urban agriculture, due to the challenges of quantifying its benefits and the relative scarcity of open space in the developed city. Yet, these challenges proved insufficient to prevent a coalition of civic activists working in collaboration with public officials to envision plans on food policy that included urban agriculture. Actors created the ‘local/regional food system’ as a narrative concept in order to build broad coalitions and gain entry to the municipal policy sphere. Tracing the roll-out of plans reveals the way in which both the food systems concept and specific policy proposals were repeated and legitimized.Unpacking the dynamics of this iterative policymaking contributes to an understanding of how urban environmental governance happens in this case

Getting farming on the agenda: Planning, policymaking, and governance practices of urban agriculture in New York City

How and why is urban agriculture taken up into local food policies and sustainability plans? This paper uses a case study of urban agriculture policymaking in New York City from 2007 to 2011 to examine the power-laden operation of urban environmental governance. It explores several ‘faces of power,’ including overt authority, institutionalized ‘rules of the game,’ and hegemony. It also investigates how multiple actors interact in policymaking processes, including through the construction and use of broad discursive concepts. Findings draw upon analysis of policy documents and semi-structured interviews with 43 subjects engaged in food systems policymaking. Some municipal decision-makers questioned the significance of urban agriculture, due to the challenges of quantifying its benefits and the relative scarcity of open space in the developed city. Yet, these challenges proved insufficient to prevent a coalition of civic activists working in collaboration with public officials to envision plans on food policy that included urban agriculture. Actors created the ‘local/regional food system’ as a narrative concept in order to build broad coalitions and gain entry to the municipal policy sphere. Tracing the roll-out of plans reveals the way in which both the food systems concept and specific policy proposals were repeated and legitimized.Unpacking the dynamics of this iterative policymaking contributes to an understanding of how urban environmental governance happens in this case

Cool Japan and the Hallyu Wave: The Effect of Popular Culture Exports on National Image and Soft Power

Japan used its export of pop culture in the post-war era not only to boost its economy but also as a means to improve its national image and project its soft power. Japanese pop culture exports emphasized a positive, non-threatening image of national culture. Though Japan’s pop culture export boom has been enormously successful, it has not been able to completely overcome its problematic past and erase historical tensions with Korea and other Asian nations. The pop culture boom has redefined Japan’s national image but not entirely. Contradictions between Japan’s curated image and actual reality, especially in the case of indigenous and ethnic minorities, also pose a challenge to Japan’s efforts to create a positive national image based on peaceful coexistence. Korea’s Hallyu Wave has been garnering more popularity and attention. The Hallyu Wave has innovative products and methods to spread South Korean pop-culture, it is use to create better relations with countries worldwide. It is similar to Japan’s Pop-Culture Boom because the Hallyu Wave aims to promote the most positive national and international image of South Korea

Discrete Breathers

Nonlinear classical Hamiltonian lattices exhibit generic solutions in the form of discrete breathers. These solutions are time-periodic and (typically exponentially) localized in space. The lattices exhibit discrete translational symmetry. Discrete breathers are not confined to certain lattice dimensions. Necessary ingredients for their occurence are the existence of upper bounds on the phonon spectrum (of small fluctuations around the groundstate) of the system as well as the nonlinearity in the differential equations. We will present existence proofs, formulate necessary existence conditions, and discuss structural stability of discrete breathers. The following results will be also discussed: the creation of breathers through tangent bifurcation of band edge plane waves; dynamical stability; details of the spatial decay; numerical methods of obtaining breathers; interaction of breathers with phonons and electrons; movability; influence of the lattice dimension on discrete breather properties; quantum lattices - quantum breathers. Finally we will formulate a new conceptual aproach capable of predicting whether discrete breather exist for a given system or not, without actually solving for the breather. We discuss potential applications in lattice dynamics of solids (especially molecular crystals), selective bond excitations in large molecules, dynamical properties of coupled arrays of Josephson junctions, and localization of electromagnetic waves in photonic crystals with nonlinear response.Comment: 62 pages, LaTeX, 14 ps figures. Physics Reports, to be published; see also at http://www.mpipks-dresden.mpg.de/~flach/html/preprints.htm

Religions and Trade

Religions and Trade carves new pathways into the world of religious dynamics. In this array of essays a number of international scholars investigate the ways in which eastern and western religions were formed and transformed from the perspective of “trade.”; Readership: All people interested in the formation of religion and interreligious dynamics, and anyone concerned with cross-cultural exchange between east and west

Computational efficiency of numerical integration methods for the tangent dynamics of many-body Hamiltonian systems in one and two spatial dimensions

We investigate the computational performance of various numerical methods for the integration of the equations of motion and the variational equations for some typical classical many-body models of condensed matter physics: the Fermi-Pasta-Ulam-Tsingou (FPUT) chain and the one- and two-dimensional disordered, discrete nonlinear Schr\"odinger equations (DDNLS). In our analysis we consider methods based on Taylor series expansion, Runge-Kutta discretization and symplectic transformations. The latter have the ability to exactly preserve the symplectic structure of Hamiltonian systems, which results in keeping bounded the error of the system's computed total energy. We perform extensive numerical simulations for several initial conditions of the studied models and compare the numerical efficiency of the used integrators by testing their ability to accurately reproduce characteristics of the systems' dynamics and quantify their chaoticity through the computation of the maximum Lyapunov exponent. We also report the expressions of the implemented symplectic schemes and provide the explicit forms of the used differential operators. Among the tested numerical schemes the symplectic integrators $ABA864$ and $SRKN^a_{14}$ exhibit the best performance, respectively for moderate and high accuracy levels in the case of the FPUT chain, while for the DDNLS models $s9\mathcal{ABC}6$ and $s11\mathcal{ABC}6$ (moderate accuracy), along with $s17\mathcal{ABC}8$ and $s19\mathcal{ABC}8$ (high accuracy) proved to be the most efficient schemes.Comment: Accepted for publication in Mathematics in Engineerin