Searching for binary coalescences with inspiral templates: Detection and parameter estimation

There has been remarkable progress in numerical relativity recently. This has led to the generation of gravitational waveform signals covering what has been traditionally termed the three phases of the coalescence of a compact binary - the inspiral, merger and ringdown. In this paper, we examine the usefulness of inspiral only templates for both detection and parameter estimation of the full coalescence waveforms generated by numerical relativity simulations. To this end, we deploy as search templates waveforms based on the effective one-body waveforms terminated at the light-ring as well as standard post-Newtonian waveforms. We find that both of these are good for detection of signals. Parameter estimation is good at low masses, but degrades as the mass of the binary system increases.Comment: 14 pages, submitted to proceedings of the NRDA08 meeting, Syracuse, Aug. 11-14, 200

Gravitational-wave Science in the High School Classroom

This article describes a set of curriculum modifications designed to integrate gravitational-wave science into a high school physics or astronomy curriculum. Gravitational-wave scientists are on the verge of being able to detect extreme cosmic events, like the merger of two black holes, happening hundreds of millions of light years away. Their work has the potential to propel astronomy into a new era by providing an entirely new means of observing astronomical phenomena. Gravitational-wave science encompasses astrophysics, physics, engineering, and quantum optics. As a result, this curriculum exposes students to the interdisciplinary nature of science. It also provides an authentic context for students to learn about astrophysical sources, data analysis techniques, cutting-edge detector technology, and error analysis.Comment: Submitted to the American Journal of Physic

Basic Parameter Estimation of Binary Neutron Star Systems by the Advanced LIGO/Virgo Network

Within the next five years, it is expected that the Advanced LIGO/Virgo network will have reached a sensitivity sufficient to enable the routine detection of gravitational waves. Beyond the initial detection, the scientific promise of these instruments relies on the effectiveness of our physical parameter estimation capabilities. The majority of this effort has been towards the detection and characterization of gravitational waves from compact binary coalescence, e.g. the coalescence of binary neutron stars. While several previous studies have investigated the accuracy of parameter estimation with advanced detectors, the majority have relied on approximation techniques such as the Fisher Matrix. Here we report the statistical uncertainties that will be achievable for optimal detection candidates (SNR = 20) using the full parameter estimation machinery developed by the LIGO/Virgo Collaboration via Markov-Chain Monte Carlo methods. We find the recovery of the individual masses to be fractionally within 9% (15%) at the 68% (95%) credible intervals for equal-mass systems, and within 1.9% (3.7%) for unequal-mass systems. We also find that the Advanced LIGO/Virgo network will constrain the locations of binary neutron star mergers to a median uncertainty of 5.1 deg^2 (13.5 deg^2) on the sky. This region is improved to 2.3 deg^2 (6 deg^2) with the addition of the proposed LIGO India detector to the network. We also report the average uncertainties on the luminosity distances and orbital inclinations of ideal detection candidates that can be achieved by different network configurations.Comment: Second version: 15 pages, 9 figures, accepted in Ap

A comparison of steady, pulsating flow measurements and CFD simulations in close coupled catalysts

Performance improvements of automotive catalytic converters can be achieved by improving the flow distribution of exhaust gases within the substrate. The flow distribution is often assumed to be adequately described by measurements obtained from steady flow rigs. An experimental study was carried out to characterise the flow distribution through the substrate of a close-coupled catalytic converter for both steady and pulsating conditions on a flow rig and on a motored engine. Computational fluid dynamic (CFD) simulations were also performed. On the flow rig, the flow from each port was activated separately discharging air to different regions of the substrate. This resulted in a high degree of flow maldistribution. For steady flow maldistribution increased with Reynolds number. Pulsating the flow resulted in a reduction in flow maldistribution. Different flow distributions were observed on the motored engine when compared to composite maps derived from the rig. For the engine study significantly more flow activity was observed at the periphery of the substrate, each port contributing to the net flow. The results suggest that strong port interactions occur. CFD simulations showed qualitative agreement with measurements but underestimated the flow maldistribution. Publisher statement: Copyright © 2001 SAE International. This paper is posted on this site with permission from SAE International and is for viewing only. It may not be stored on any additional repositories or retrieval systems. Further use or distribution is not permitted without permission from SAE

Systematic and statistical errors in a Bayesian approach to the estimation of the neutron-star equation of state using advanced gravitational wave detectors

Advanced ground-based gravitational-wave detectors are capable of measuring tidal influences in binary neutron-star systems. In this work, we report on the statistical uncertainties in measuring tidal deformability with a full Bayesian parameter estimation implementation. We show how simultaneous measurements of chirp mass and tidal deformability can be used to constrain the neutron-star equation of state. We also study the effects of waveform modeling bias and individual instances of detector noise on these measurements. We notably find that systematic error between post-Newtonian waveform families can significantly bias the estimation of tidal parameters, thus motivating the continued development of waveform models that are more reliable at high frequencies

Seeing with New Eyes:Designing for In-the-Wild Museum Gifting

This paper presents the GIFT smartphone app, an artist-led Research through Design project benefitting from a three-day in-the-wild deployment. The app takes as its premise the generative potential of combining the contexts of gifting and museum visits. Visitors explore the museum, searching for objects that would most appeal to the gift-receiver they have in mind, then photographing those objects and adding audio messages for their receivers describing the motivation for their choices. This paper charts the designers' key aim of creating a new frame of mind using voice, and the most striking findings discovered during in-the-wild deployment in a museum -- 'seeing with new eyes' and fostering personal connections. We discuss empathy, motivation, and bottom-up personalisation in the productive space revealed by this combination of contexts. We suggest that this work reveals opportunities for designers of gifting services as well as those working in cultural heritage

Time evolution of a non-singular primordial black hole

There is growing notion that black holes may not contain curvature singularities (and that indeed nature in general may abhor such spacetime defects). This notion could have implications on our understanding of the evolution of primordial black holes (PBHs) and possibly on their contribution to cosmic energy. This paper discusses the evolution of a non-singular black hole (NSBH) based on a recent model [1]. We begin with a study of the thermodynamic process of the black hole in this model, and demonstrate the existence of a maximum horizon temperature T_{max}, corresponding to a unique mass value. At this mass value the specific heat capacity C changes signs to positive and the body begins to lose its black hole characteristics. With no loss of generality, the model is used to discuss the time evolution of a primordial black hole (PBH), through the early radiation era of the universe to present, under the assumption that PBHs are non-singular. In particular, we track the evolution of two benchmark PBHs, namely the one radiating up to the end of the cosmic radiation domination era, and the one stopping to radiate currently, and in each case determine some useful features including the initial mass m_{f} and the corresponding time of formation t_{f}. It is found that along the evolutionary history of the universe the distribution of PBH remnant masses (PBH-RM) PBH-RMs follows a power law. We believe such a result can be a useful step in a study to establish current abundance of PBH-MRs.Comment: To appear in Int. J. Mod. Phys.

The Miskito Settlement Landscape of Eastern Honduras, With Emphasis on the Moravian Contribution.

This dissertation documents the influence of Moravian missionary activities on the Miskito settlement landscape in eastern Honduras---particularly in the areas of settlement morphology, housing, agriculture, and cemeteries. Upon their arrival to the Mosquito Coast in 1849, the missionaries employed a three pronged approach consisting of proselyting, medical treatment, and education to convert the majority of the indigenous population. The missionaries\u27 resulting influence was a significant component and major cultural force in the development of a distinctive Protestant region within Catholic Central America. Moravian contributions to the settlement landscape in sixty-four Miskito villages of eastern Honduras were documented through field observations of material culture, interviews, photographs, and document research in the Moravian Church archives. This information was used to map a hierarchy of Moravian centers illustrating spatially varying degrees of Moravian influence on the Miskito settlement landscape. Principal findings included: (1) Missionaries\u27 modified Miskito settlement morphology by implementing a distinctive settlement type based on the Hurrnhut model whereby church buildings were located on a central square that was bisected by the village road; (2) Moravian church architecture in Honduras passed through three stages beginning with local forms and materials, continuing with European forms and both local and manufactured materials, and concluding with only imported, manufactured materials; (3) Moravian alterations to Miskito housing consisted of changes to form and materials including such the installation of outside walls and inside partitions, frame construction raised above the ground on posts, and the addition of an external kitchen and gallery; (4) Moravian influence on Miskito agriculture included the introduction of new seed crops, increased fruit tree cultivation, and the expansion of traditional dooryard gardens; (5) Missionaries modified Miskito burial practices by discouraging both the isingni ceremony and property destruction, and by instituting the Moravian Easter Dawn Service. Through the analysis of cultural landscapes this dissertation builds a greater understanding of (1) the role of religion in creating ethnic landscapes; (2) the historical and cultural processes involved in the development of a Protestant cultural region within Catholic Central America; and (3) how cultural landscapes may be used by indigenous, peoples to document claims to ancestral lands