Gravitational radiation from the r-mode instability

The instability in the r-modes of rotating neutron stars can (in principle) emit substantial amounts of gravitational radiation (GR) which might be detectable by LIGO and similar detectors. Estimates are given here of the detectability of this GR based the non-linear simulations of the r-mode instability by Lindblom, Tohline and Vallisneri. The burst of GR produced by the instability in the rapidly rotating 1.4 solar mass neutron star in this simulation is fairly monochromatic with frequency near 960 Hz and duration about 100 s. A simple analytical expression is derived here for the optimal S/N for detecting the GR from this type of source. For an object located at a distance of 20 Mpc we estimate the optimal S/N to be in the range 1.2 to about 12.0 depending on the LIGO II configuration.Comment: 8 pages, 4 figure

The Relaxation Effect in Dissipative Relativistic Fluid Theories

The dynamics of the fluid fields in a large class of causal dissipative fluid theories is studied. It is shown that the physical fluid states in these theories must relax (on a time scale that is characteristic of the microscopic particle interactions) to ones that are essentially indistinguishable from the simple relativistic Navier-Stokes descriptions of these states. Thus, for example, in the relaxed form of a physical fluid state the stress energy tensor is in effect indistinguishable from a perfect fluid stress tensor plus small dissipative corrections proportional to the shear of the fluid velocity, the gradient of the temperature, etc.Comment: Plain TeX -- 16 Page

Optimal Calibration Accuracy for Gravitational Wave Detectors

Calibration errors in the response function of a gravitational wave detector degrade its ability to detect and then to measure the properties of any detected signals. This paper derives the needed levels of calibration accuracy for each of these data-analysis tasks. The levels derived here are optimal in the sense that lower accuracy would result in missed detections and/or a loss of measurement precision, while higher accuracy would be made irrelevant by the intrinsic noise level of the detector. Calibration errors affect the data-analysis process in much the same way as errors in theoretical waveform templates. The optimal level of calibration accuracy is expressed therefore as a joint limit on modeling and calibration errors: increased accuracy in one reduces the accuracy requirement in the other.Comment: v2: minor changes, updated to version accepted in Phys. Rev.

Phase Transitions and the Mass-Radius Curves of Relativistic Stars

The properties of the mass-radius curves of relativistic stellar models constructed from an equation of state with a first-order phase transition are examined. It is shown that the slope of the mass-radius curve is continuous unless the discontinuity in the density at the phase transition point has a certain special value. The curve has a cusp if the discontinuity is larger than this value. The curvature of the mass-radius curve becomes singular at the point where the high density phase material first appears. This singularity makes the mass-radius curve appear on large scales to have a discontinuity in its slope at this point, even though the slope is in fact continuous on microscopic scales. Analytical formulae describing the behavior of these curves are found for the simple case of models with two-zone uniform-density equations of state.Comment: 9 Pages, 4 Figure

Use and Abuse of the Model Waveform Accuracy Standards

Accuracy standards have been developed to ensure that the waveforms used for gravitational-wave data analysis are good enough to serve their intended purposes. These standards place constraints on certain norms of the frequency-domain representations of the waveform errors. Examples are given here of possible misinterpretations and misapplications of these standards, whose effect could be to vitiate the quality control they were intended to enforce. Suggestions are given for ways to avoid these problems.Comment: v2: updated to version published in Phys. Rev. D; 10 pages, 7 figure

Effectively Regulating E-Cigarettes and Their Advertising—and the First Amendment

If tobacco smoking did not exist in the United States, there would be no reason, from a public health perspective, to allow addictive, nicotine-containing e-cigarettes to be marketed and sold. Because e-cigarette use, by itself, is neither beneficial nor benign to users and nonusers, the only public health justification for allowing e-cigarettes in the existing U.S. market would be if doing so would not sustain or increase existing smoking levels but would help smokers quit completely or provide addicted smokers a less harmful way to obtain the nicotine they crave. Yet e-cigarettes are now pervasive in the U.S. market, being sold with unnecessary harmful characteristics and being advertised in ways that encourage youth experimentation and use. Unless effectively regulated, e-cigarette use will be more harmful than necessary and their advertising will work to: (a) increase initiation among both youth and non-tobacco-using adults; (b) prompt former smokers to relapse back into addicted nicotine use; (c) encourage smokers to use e-cigarettes where they cannot smoke; and (d) prompt smokers to switch to e-cigarettes instead of quitting all tobacco and nicotine use. This paper proposes a viable way to regulate e-cigarettes and their advertising both to minimize the health harms they might cause and to allow e-cigarettes to fulfill their potential as cessation aids or harm-reduction products. Normally, any efforts by FDA to establish effective advertising restrictions must accommodate considerable constraints from the First Amendment’s commercial speech protections. However, because of existing text in the Tobacco Control Act, on the effective date of the final FDA deeming rule that puts e-cigarettes under FDA’s active tobacco product jurisdiction all nicotine-containing e-cigarettes will be on the U.S. market illegally until they can obtain permissive orders from FDA. That situation should reduce applicable First Amendment constraints, providing FDA with a tremendous opportunity to place the kinds of substantial restrictions and requirements on e-cigarette advertising necessary to minimize their harmful aspects and maximize their potential to produce substantial net public health benefits

Filling in the Blanks on Reducing Tobacco Product Addictiveness in the FCTC Partial Guidelines for Articles 9 & 10

The existing Partial Guidelines for Implementation of Articles 9 & 10 of the WHO Framework Convention for Tobacco Control includes a strategy for regulating tobacco products to reduce their attractiveness, but does not yet provide any guidance for reducing either the toxicity or the addictiveness of tobacco products. Section 1.2.1.2, “Addictiveness (dependence liability),” states only that: “This section has been left blank intentionally to indicate that guidance will be proposed at a later stage.” A related footnote says that the blanks will be filled “as new country experience, and scientific, medical and other evidence become available. . . [and] will also depend on the validation of the analytical chemical methods for testing and measuring cigarette contents and emissions.” This article details that sufficient evidence and accurate testing methods are now available to begin providing useful guidance to countries that have the capacity to implement new measures to reduce the addictiveness of tobacco products and enforce compliance. Using the format of the existing partial guidelines, this working paper suggests possible draft text for the blank “Addictiveness” section, followed by a concise summary of supporting research and analysis