Scale dependence of fNLf_{NL} in N-flation

Adopting the horizon-crossing approximation, we derive the spectral index of $f_{NL}$ in general N-flation model. Axion N-flation model is taken as a typical model for generating a large $f_{NL}$ which characterizes the size of local form bispectrum. We find that its tilt $n_{f_{NL}}$ is negligibly small when all inflatons have the same potential, but a negative detectable $n_{f_{NL}}$ can be achieved in the axion N-flation with different decay constants for different inflatons. The measurement of $n_{f_{NL}}$ can be used to support or falsify the axion N-flation in the near future.Comment: 15 pages, 2 figures; a subsection with detectable scale dependence of f_NL added; more discussions added and version accepted for publication in JCA

Gravity and non-gravity mediated couplings in multiple-field inflation

Mechanisms for the generation of primordial non-Gaussian metric fluctuations in the context of multiple-field inflation are reviewed. As long as kinetic terms remain canonical, it appears that nonlinear couplings inducing non-gaussianities can be split into two types. The extension of the one-field results to multiple degrees of freedom leads to gravity mediated couplings that are ubiquitous but generally modest. Multiple-field inflation offers however the possibility of generating non-gravity mediated coupling in isocurvature directions that can eventually induce large non-Gaussianities in the metric fluctuations. The robustness of the predictions of such models is eventually examined in view of a case study derived from a high-energy physics construction.Comment: 14 pages, 3 figures, invited review for CQG issue on non-linear cosmolog

Inhomogeneous non-Gaussianity

We propose a method to probe higher-order correlators of the primordial density field through the inhomogeneity of local non-Gaussian parameters, such as f_NL, measured within smaller patches of the sky. Correlators between n-point functions measured in one patch of the sky and k-point functions measured in another patch depend upon the (n+k)-point functions over the entire sky. The inhomogeneity of non-Gaussian parameters may be a feasible way to detect or constrain higher-order correlators in local models of non-Gaussianity, as well as to distinguish between single and multiple-source scenarios for generating the primordial density perturbation, and more generally to probe the details of inflationary physics.Comment: 16 pages, 2 figures; v2: Minor changes and references added. Matches the published versio

Antiturst Law-Exemptions for Regulated Industries - Applicability of the Antitrust Laws to Stock Exchanges

Defendant, the New York Stock Exchange, directed its members to discontinue their direct private wire connections with plaintiffs who were non-member brokers. These private wire connections were utilized primarily for facilitating transactions in the over-the-counter market. Repeated requests by plaintiffs for reinstatement were ignored, and the defendant refused to apprise the plaintiffs of the reasons for its action. Plaintiffs then brought suit, seeking damages and injunctive relief pursuant to sections 4 and 16 of the Clayton Act. Maintaining that defendant\u27s conduct violated section 1 of the Sherman Act, plaintiffs moved for summary judgment. Held, motion granted.6 Defendant does not enjoy an exemption from the antitrust laws. The conduct of it and its members constituted a concerted refusal to deal, which is a per se violation of the Sherman Act. Silver v. New York Stock Exchange, 196 F. Supp. 209 (S.D.N.Y. 1961)

Negligence-\u3cem\u3eRes lpsa Loquitur\u3c/em\u3e-Application to Medical Malpractice Actions: 1951-196

Res ipsa loquitur, the thing speaks for itself, has been the subject matter of extensive legal literature since its inception almost a century ago. It is now well settled that res ipsa loquitur is no more than an inference of negligence from circumstantial evidence. The doctrine is applicable if an act or occurrence is of the type that ordinarily would not take place without negligence, assuming the plaintiff has himself been passive, and if the instrumentality causing the harm is within the exclusive control of the defendant. The application of res ipsa loquitur to the medical malpractice area has introduced a number of problems, both legal and philosophical, resulting in a wide diversity of opinion as to whether the doctrine should be any more sparingly applied in medical negligence cases than it should in cases of exploding bottles, airplane crashes or similar unexpected events. It is often stated that expert medical testimony is a prerequisite to the establishment of a malpractice claim, except in the clearest of cases where it can be said that the result speaks for itself. Judicial reluctance to expand the number of cases in which expert testimony is not required has been the foremost obstacle to the invocation of the doctrine. The reasoning of the courts appears to be that, in a majority of cases of alleged malpractice, it is beyond the capability of a jury of laymen to decide whether a particular event is of the type that ordinarily would not take place had due care been exercised. Thus, a failure to fulfill the first requirement renders the doctrine unavailable. Whether or not such an approach is too formalistic is arguable. There are, however, valid arguments that can be suggested for permitting the use of res ipsa loquitur in the medical negligence field. First, although expert testimony would be desirable, it is often impossible to procure. The general reluctance of physicians to testify against one another is well known, although characterization of this as a conspiracy of silence is questionable. But regardless of the motivation for their unwillingness, it is clear that a plaintiff in a medical malpractice action operates under a serious handicap in obtaining expert medical witnesses. Second, in many cases of medical or surgical treatment the knowledge of the facts is peculiarly within the possession of the doctor. More often than not, the plaintiff was unconscious or totally ignorant of the procedures that were employed. Third, the confidence and trust reposed in the doctor by a patient demands that the former come forward with some explanation of what went wrong. Finally, it is maintained that the doctrine should not be any less available to a plaintiff merely because he happens to be suing a doctor, rather than a bottle manufacturer or an airline

Space Trajectory Error Analysis Program (STEAP) for halo orbit missions. Volume 2: Programmer's manual

The six month effort was responsible for the development, test, conversion, and documentation of computer software for the mission analysis of missions to halo orbits about libration points in the earth-sun system. The software consisting of two programs called NOMNAL and ERRAN is part of the Space Trajectories Error Analysis Programs. The program NOMNAL targets a transfer trajectory from earth on a given launch date to a specified halo orbit on a required arrival date. Either impulsive or finite thrust insertion maneuvers into halo orbit are permitted by the program. The transfer trajectory is consistent with a realistic launch profile input by the user. The second program ERRAN conducts error analyses of the targeted transfer trajectory. Measurements including range, doppler, star-planet angles, and apparent planet diameter are processed in a Kalman-Schmidt filter to determine the trajectory knowledge uncertainty

Scale-dependent non-Gaussianity probes inflationary physics

We calculate the scale dependence of the bispectrum and trispectrum in (quasi) local models of non-Gaussian primordial density perturbations, and characterize this scale dependence in terms of new observable parameters. They can help to discriminate between models of inflation, since they are sensitive to properties of the inflationary physics that are not probed by the standard observables. We find consistency relations between these parameters in certain classes of models. We apply our results to a scenario of modulated reheating, showing that the scale dependence of non-Gaussianity can be significant. We also discuss the scale dependence of the bispectrum and trispectrum, in cases where one varies the shape as well as the overall scale of the figure under consideration. We conclude providing a formulation of the curvature perturbation in real space, which generalises the standard local form by dropping the assumption that f_NL and g_NL are constants.Comment: 27 pages, 2 figures. v2: Minor changes to match the published versio

Scale-Dependent Non-Gaussianity as a Generalization of the Local Model

We generalize the local model of primordial non-Gaussianity by promoting the parameter fNL to a general scale-dependent function fNL(k). We calculate the resulting bispectrum and the effect on the bias of dark matter halos, and thus the extent to which fNL(k) can be measured from the large-scale structure observations. By calculating the principal components of fNL(k), we identify scales where this form of non-Gaussianity is best constrained and estimate the overlap with previously studied local and equilateral non-Gaussian models.Comment: Accepted to JCAP. 22 pages, 4 figure