Long-short wavelength mode coupling tightens primordial black hole constraints

The effects of non-Gaussianity on the constraints on the primordial curvature perturbation power spectrum from primordial black holes (PBHs) are considered. We extend previous analyses to include the effects of coupling between the modes of the horizon scale at the time the PBH forms and superhorizon modes. We consider terms of up to third order in the Gaussian perturbation. For the weakest constraints on the abundance of PBHs in the early universe (corresponding to a fractional energy density of PBHs of 10−5 at the time of formation), in the case of Gaussian perturbations, constraints on the power spectrum are Pζ<0.05 but can be significantly tighter when even a small amount of non-Gaussianity is considered, to Pζ<0.01, and become approximately Pζ<0.003 in more special cases. Surprisingly, even when there is negative skew (which naively would suggest fewer areas of high density, leading to weaker constraints), we find that the constraints on the power spectrum become tighter than the purely Gaussian case—in strong contrast with previous results. We find that the constraints are highly sensitive to both the non-Gaussianity parameters as well as the amplitude of superhorizon perturbations

The Friedman's and Mishkin's Hypotheses (Re)Considered

This paper o¤ers to investigate both the Friedman's and Mishkin's hypotheses on the consequences of inflation on output growth. To this end, we first base these hypotheses in a unified framework. Second, in an empirical work based on OECD countries, we distinguish between short-medium and long run and between headline and core inflation. We get two main results. First, nominal uncertainty and inflation are positively linked. Second, headline inflation negatively Granger causes out- put gap (US, Japan, France) but has no effect on potential output growth (US excepted) whereas core inflation impacts potential output growth (UK, Germany) but not output gap (US excepted).Inflation, uncertainty, output growth, GARCH, CF filter

A Recurrent Neural Model with Attention for the Recognition of Chinese Implicit Discourse Relations

We introduce an attention-based Bi-LSTM for Chinese implicit discourse relations and demonstrate that modeling argument pairs as a joint sequence can outperform word order-agnostic approaches. Our model benefits from a partial sampling scheme and is conceptually simple, yet achieves state-of-the-art performance on the Chinese Discourse Treebank. We also visualize its attention activity to illustrate the model's ability to selectively focus on the relevant parts of an input sequence.Comment: To appear at ACL2017, code available at https://github.com/sronnqvist/discourse-ablst

Swearwords Used by Gangsters in the “Alpha Dog” Movie

Many people assume that swearwords is a rude word and should be avoided. Those words are used to insult, to curse, to offend or to mock at something when the speaker has strong emotion (Hughes, 1991,05). To swear at someone or something is to insult and deprecate the object of abuse, as well as to use other kinds of dysphemism (Allan &amp; Burridge, 2006,76). Apparently some experts and scholars have been able to prove that swearwords also has a purpose and a meaning beside the one as commonly held. Therefore, the writer took the "Alpha Dog" movie as an example of the analyzed cases. Examples have been found by the writer including the categories of epithets derived from tabooed bodily organs, epithets derived from bodily effluvia, epithets derived from sexual behaviours, dysphemistic epithets that pick on real physical characteristics that are treated as though they are abnormalities, imprecations and epithets invoking mental subnormality or derangement. Finally, the writer also managed to find a purpose or a reason for the people to use swearwords in real life

Security-voting structure and bidder screening

This paper analyzes how non-voting shares affect the takeover outcome in a single-bidder model with asymmetric information and private benefit extraction. In equilibrium, the target firm’s security-voting structure influences the bidder’s participation constraint and in response the shareholders’ conditional expectations about the post-takeover share value. Therefore, the structure can be chosen to discriminate among bidder types. Typically, the socially optimal structure deviates from one share - one vote to promote all and only value-increasing bids. As target shareholders ignore takeover costs, they prefer more takeovers and hence choose a smaller fraction of voting shares than is socially optimal. In either case, the optimal fraction of voting shares decreases with the quality of shareholder protection and increases with the incumbent manager’s ability. Finally, shareholder returns are higher when a given takeover probability is implemented by (more) non-voting shares rather than by (larger) private benefits

Bostonia: The Boston University Alumni Magazine. Volume 37

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

'Modal-noise' in single-mode fibers: A cautionary note for high precision radial velocity instruments

Exploring the use of single-mode fibers (SMFs) in high precision Doppler spectrometers has become increasingly attractive since the advent of diffraction-limited adaptive optics systems on large-aperture telescopes. Spectrometers fed with these fibers can be made significantly smaller than typical 'seeing-limited' instruments, greatly reducing cost and overall complexity. Importantly, classical mode interference and speckle issues associated with multi-mode fibers, also known as 'modal noise', are mitigated when using SMFs, which also provide perfect radial and azimuthal image scrambling. However, these fibers do support multiple polarization modes, an issue that is generally ignored for larger-core fibers given the large number of propagation modes. Since diffraction gratings used in most high resolution astronomical instruments have dispersive properties that are sensitive to incident polarization changes, any birefringence variations in the fiber can cause variations in the efficiency profile, degrading illumination stability. Here we present a cautionary note outlining how the polarization properties of SMFs can affect the radial velocity measurement precision of high resolution spectrographs. This work is immediately relevant to the rapidly expanding field of diffraction-limited, extreme precision RV spectrographs that are currently being designed and built by a number of groups.Comment: 6 pages, 5 figures, accepted for publication in ApJ Letter