Aspects of Noncommutative Scalar/Tensor Duality

We study the noncommutative massless Kalb-Ramond gauge field coupled to a dynamical U(1) gauge field in the adjoint representation together with a compensating vector field. We derive the Seiberg-Witten map and obtain the corresponding mapped action to first order in $\theta$. The (emergent) gravity structure found in other situations is not present here. The off-shell dual scalar theory is derived and it does not coincide with the Seiberg-Witten mapped scalar theory. Dispersion relations are also discussed. The p-form generalization of the Seiberg-Witten map to order $\theta$ is also derived.Comment: 7 pages, typos corrected, a footnote removed and a sentence added in the tex

Complete phenomenological gravitational waveforms from spinning coalescing binaries

The quest for gravitational waves from coalescing binaries is customarily performed by the LIGO-Virgo collaboration via matched filtering, which requires a detailed knowledge of the signal. Complete analytical coalescence waveforms are currently available only for the non-precessing binary systems. In this paper we introduce complete phenomenological waveforms for the dominant quadrupolar mode of generically spinning systems. These waveforms are constructed by bridging the gap between the analytically known inspiral phase, described by spin Taylor (T4) approximants in the restricted waveform approximation, and the ring-down phase through a phenomenological intermediate phase, calibrated by comparison with specific, numerically generated waveforms, describing equal mass systems with dimension-less spin magnitudes equal to 0.6. The overlap integral between numerical and phenomenological waveforms ranges between 0.95 and 0.99.Comment: Proceeding for the GWDAW-14 conference. Added reference in v

On Dual Formulations of Massive Tensor Fields

In this paper we investigate dual formulations for massive tensor fields. Usual procedure for construction of such dual formulations based on the use of first order parent Lagrangians in many cases turns out to be ambiguous. We propose to solve such ambiguity by using gauge invariant description of massive fields which works both in Minkowski space as well as (Anti) de Sitter spaces. We illustrate our method by two concrete examples: spin-2 "tetrad" field h_{\mu a}, the dual field being "Lorentz connection" \omega_{\mu,ab} and "Riemann" tensor R_{\mu\nu,ab} with the dual \Sigma_{\mu\nu,abc}.Comment: 9 pages, plain LaTe

Forest landscape ecology and global change: what are the next steps?

In this chapter, we summarize current trends and challenges and future research directions in forest landscape ecology and in management related to global change. We discuss the available knowledge in forest landscape ecology and the possibilities of using this knowledge to support management under changing conditions. We also discuss the forest sector’s preparedness to deal with changes in management and how forest landscape ecology can guide this management. Forest landscape ecology has gathered substantial knowledge on patterns, processes, tools, and methods that can support forest and landscape management during changing scenarios. We recognize that existing knowledge is incomplete and that a substantial portion of our knowledge is uncertain, that variability in landscape conditions and various forms of error compound the problem, that we still lack considerable knowledge in some fields, and that there are likely to be knowledge gaps we are not aware of. We nonetheless face the challenge of responding to change based on the available knowledge

Optimal time-domain combination of the two calibrated output quadratures of GEO 600

GEO 600 is an interferometric gravitational wave detector with a 600 m arm-length and which uses a dual-recycled optical configuration to give enhanced sensitivity over certain frequencies in the detection band. Due to the dual-recycling, GEO 600 has two main output signals, both of which potentially contain gravitational wave signals. These two outputs are calibrated to strain using a time-domain method. In order to simplify the analysis of the GEO 600 data set, it is desirable to combine these two calibrated outputs to form a single strain signal that has optimal signal-to-noise ratio across the detection band. This paper describes a time-domain method for doing this combination. The method presented is similar to one developed for optimally combining the outputs of two colocated gravitational wave detectors. In the scheme presented in this paper, some simplifications are made to allow its implementation using time-domain methods

Forest landscapes and global change: Challenges for research and management

Climate change, urban sprawl, abandonment of agriculture, intensifi cation of forestry and agriculture, changes in energy generation and use, expansion of infrastructure networks, habitat destruction and degradation, and other drivers and pressures of change are occurring at increasing rates globally. They affect ecological patterns and processes in forest landscapes and modify ecosystem services derived from those ecosystems. Consequently, the landscapes that are rapidly changing in response to these pressures present many new challenges to scientists and managers. Although it is not uncommon to encounter the terms “global change” and “landscape” together in the ecological literature, there has been no adequate global analysis of drivers of change in forest landscapes and their ecological consequences. Providing such an analysis is the goal of this volume: an exploration of the state of knowledge of global changes in forested landscapes, with an emphasis on their causes and effects, and the challenges faced by researchers and land managers who must cope with these changes. This book was based on the IUFRO Landscape Ecology Working Group International Conference that took place in Bragança, Portugal, in September 2010 under the theme “Forest Landscapes and Global Change: New Frontiers in Management, Conservation and Restoration”. The event brought together more than 300 landscape ecologists from almost 50 countries and 5 continents, who came to expand their knowledge and awareness of global changes in forest landscapes. We hope that the syntheses in this book, prepared by a diverse group of scientists who participated in the conference, will enhance the global understanding of a range of topics relevant to change in forest landscapes and stimulate new research to answer the questions raised by these authors. First, we introduce the broad topic of forest landscape ecology and global change. This is followed by chapters that identify and describe major agents of landscape change: climate (Iverson et al.), wildfi re (Rego and Silva), and human activities (Farinaci et al.). The next chapters address implications of change for ecosystem services (Marta-Pedroso et al.), carbon fl uxes (Chen et al.), and biodiversity conservation (Saura et al.). A subsequent chapter describes methodologies for detecting and monitoring landscape changes (Gómez-Sanz et al.) and is followed by a chapter that highlights the many challenges facing forest landscape managers amidst global change (Coulson et al.). Finally, we present a summary and a synthesis of the main points presented in the book (Azevedo et al.). Each chapter was inspired by the research experience of the authors, augmented by a review and synthesis of the global scientifi c literature on relevant topics, as well as critical input from multiple peer reviewers. The intended audience for this book includes graduate students, educators, and researchers in landscape ecology, conservation biology, and forestry, as well as land-use planners and managers. We trust that the wide range of topics, addressed from a global perspective by a geographically diverse group of contributing authors from Europe, North America, and South America, will make this volume attractive to a broad readership.We gratefully acknowledge the following peer reviewers who helped improve the content of this book: Berta Martín, Bill Hargrove, Bob Keane, Colin Beier, Don McKenzie, Eric Gustafson, Franz Gatzweiler, Geoff Henebry, Kurt Riitters, Maria Esther Núñez, Michael Ter-Mikaelian, Tom Nudds, and Yolanda Wiersma. As well, we thank Geoff Hart for assistance with editing and Janet Slobodien and Zachary Romano for assistance with publishing. We also thank FCT (the Foundation for Science and Technology, Portugal), CIMO (the Mountain Research Centre, Portugal), and IPB (the Polytechnic Institute of Bragança, Portugal) for their support during the preparation of this volume.info:eu-repo/semantics/publishedVersio

Dual Linearised Gravity in Arbitrary Dimensions

We construct dual formulation of linearised gravity in first order tetrad formalism in arbitrary dimensions within the path integral framework following the standard duality algorithm making use of the global shift symmetry of the tetrad field. The dual partition function is in terms of the (mixed symmetric) tensor field $\Phi_{[\nu_{1}\nu_{2}...\nu_{d-3}]\nu}$ in {\it frame-like} formulation. We obtain in d-dimensions the dual Lagrangian in a closed form in terms of field strength of the dual frame-like field. Next by coupling a source with the (linear) Riemann tensor in d-dimensions, dual generating functional is obtained. Using this an operator mapping between (linear) Riemann tensor and Riemann tensor corresponding to the dual field is derived and we also discuss the exchange of equations of motion and Bianchi identity.Comment: 14 pages, typos corrected, Published version: Class. Quantum Grav. 22(2005)538