Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Multi-messenger Observations of a Binary Neutron Star Merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ∼ 1.7 {{s}} with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of {40}-8+8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 {M}ȯ . An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ∼ 40 {{Mpc}}) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ∼10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ∼ 9 and ∼ 16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta.</p

Optimal management of fringe entry over time

In this paper, we investigate the problem of a dominant company facing entry of a "competitive fringe" (smaller competitor or fringe of smaller competitors). We seek to identify pricing and advertising (or other promotional strategies) that maximize long-term profits for the dominant firm, under possible reactions of the competitive fringe. Two main situations are considered: The firms in the fringe are price-takers, but they advertise. `` The firms in the fringe are not price-takers and advertise. The possibility of a passive reaction, in the case of a very small fringe, is considered as a particular case. We assume that the rate of change of fringe sales is dynamically related to the current sales, price and advertising efforts of both the dominant firm and the fringe. The higher the dominant firm price, the faster fringe entry. The higher dominant firm advertising effort, the slower fringe entry. Fringe advertising and pricing may counterbalance these effects. Formulating a dynamic game, with the dominant firm as a leader and the fringe as a follower, we present a new methodology for providing time-invariant feedback Stackelberg equilibrium. The methodology relies on finding the relationship between the co-state variables and the state variable. The equilibrium solution is obtained in an implicit form by solving a set of two backward differential equations. To show the applicability of our solution to real situations, we use data from the U.S. long-distance market and find optimal decision rules for AT&T facing the entry of MCI and Sprint during the 1980-1990 period. The feedback equilibrium indicates that while AT&T's price is decreasing when fringe (MCI and Sprint) sales increase, the fringe price is increasing. AT&T's advertising is increasing with fringe sales while the fringe's advertising increases and then decreases. The comparison with actual behavior indicates that AT&T has adhered closer to the optimal solution in both price and advertising than the fringe. (C) 2003 Published by Elsevier B.V

Dynamic Formation of Quality Expectations: Theory and Empirical Evidence

The evolution of quality expectations over time is an important driver of customer satisfaction and retention. This study investigated the dynamic prop- erties of customers’ quality expectation updating from an analytical perspective and provides new evidence on the psychological correlates of the discrepancies between expectations and experiences in the realm of consumer decision making. In doing so, we focus on the dynamics of expectation formation by adopting a nonlinear complex systems approach based on well-established behavioral the- ories. Using stability analysis, we find analytical results which are supported empirically by an experiment that there is considerable heterogeneity in how consumers calibrate their quality expectations. Specifically, we demonstrate analytically that in some cases individuals will converge to a specific quality expectation (reach a stable fixed point), while in other cases their expectations will oscillate between a small number of points periodically. This is remarkable because the existence of the latter is not due to changes in quality performance but merely accrue endogenously and depend on individuals’ disconfirmation functions. To our knowledge, this is the first time in the marketing literature that the corresponding gaps between quality expectations and quality provided are analyzed in the long run. Our analytical and empirical findings also suggest that being more responsive to a person’s expectations can increase the portion of those individuals that are able to better calibrate. Finally, we also demonstrate that calibration ability is associated with how thoughtful or impulsive information is used to update one’s expectation. A more deliberative processing style, which includes using a wider range of information, seems to be related to fewer unrealistic expectations and better calibrations, while a more impulsive processing style is related to more unrealistic expectations. In addition to providing a better understanding of dy- namic expectation formation, these results can pave the way for interventions that foster more accurate quality expectations. From a managerial perspective, our findings imply that communicating quality perceptions are only to a certain extent under managerial control. To recognize this, firms are advised to segment cus- tomers based on their information processing style and to customize their marketing actions accordingly

Moving from Customer Lifetime Value to Customer Equity

We study the consequence of moving from Customer Lifetime Value maximization to Customer Equity maximization. Customer equity has traditionally been seen as the discounted sum of the lifetime earnings from all current and future customers and thus it has been largely assumed that maximizing customer lifetime value would lead to maximum customer equity. We show that the transition from CLV to CE is not that straightforward. Although the CLV model is appropriate for managing a single non-replaceable customer, the application of a CLV model to the acquisition and valuation of customers as an ongoing concern for the firm leads to sub-optimal customer relationship management and acquisition strategies. This leads the firm following a CLV maximization approach to have a smaller and less profitable customer base than one that follows a CE maximization strategy