The Coase conjecture with incomplete information on the monopolist's commitment

A key to the Coase conjecture is the monopolist's inability to commit to a price, which leads consumers to believe that a high current price will be followed by low future prices. This paper studies the robustness of the Coase conjecture with respect to these beliefs of consumers. In particular, there is uncertainty over whether the monopolist is committed to a price (i.e. she may be a commitment type). Consequently, consumers are no longer certain that the price will change over time. I consider two kinds of commitment types. A behavioral commitment type charges an exogenously given price, while the rational commitment type optimally chooses a price. I show that the Coase conjecture is robust with regard to uncertainty over the monopolist's commitment. When the probability of behavioral types is sufficiently small, as in the original Coase conjecture, the monopolist earns the competitive profit. When the probability of behavioral types is positive, unlike in the original Coase conjecture, there is positive delay. But the delay disappears as the probability approaches zero. When the commitment type is rational, unless the probability of the commitment type is sufficiently high, both normal and committed monopolists charge the competitive price, and thus there is no delay.Coase conjecture, reputational bargaining, rational commitment

Search for Microlensing Signature in Gravitational Waves from Binary Black Hole Events

In a recent search (Kim et al. 2022), we looked for microlensing signature in gravitational waves from spectrograms of the binary black hole events in the first and second gravitational-wave transient catalogs. For the search, we have implemented a deep learning-based method (Kim et al. 2021) and figured out that one event, GW190707 093326, out of forty-six events, is classified into the lensed class. However, upon estimating the p-value of this event, we observed that the uncertainty of the p-value still includes the possibility of the event being unlensed. Therefore, we concluded that no significant evidence of beating patterns from the evaluated binary black hole events has found from the search. For a consequence study, we discuss the distinguishability between microlensed gravitational waves and the signal from precessing black hole binaries.Comment: 2 pages, 1 figure, submitted for the proceeding of the IAU Symposium 368: Machine Learning in Astronom

Dense Stellar Matter with Strange Quark Matter Driven by Kaon Condensation

The core of neutron-star matter is supposed to be at a much higher density than the normal nuclear matter density for which various possibilities have been suggested such as, for example, meson or hyperon condensation and/or deconfined quark or color-superconducting matter. In this work, we explore the implication on hadron physics of a dense compact object that has three "phases", nuclear matter at the outer layer, kaon condensed nuclear matter in the middle and strange quark matter at the core. Using a drastically simplified but not unreasonable model, we develop the scenario where the different phases are smoothly connected with the kaon condensed matter playing a role of "doorway" to a quark core, the equation of state (EoS) of which with parameters restricted within the range allowed by nature could be made compatible with the mass vs. radius constraint given by the 1.97-solar mass object PSR J1614-2230 recently observed.Comment: 18 pages, 18 figure

Triple layered compact star with strange quark matter

We explore the possibility of three phases in the core of neutron star in a form of triple layers. From the center, strange quark matter, kaon condensed nuclear matter and nuclear matter form a triple layer. We discuss how the phase of strange quark matter is smoothly connected to kaon condensed nuclear matter phase. We also demonstrate that the compact star with triple layered structure can be a model compatible with the 1.97-solar-mass object PSR J1614-2230 recently observed.Comment: 8 pages, 2 figures, to appear in the Proceedings of the Symposium on Cosmology and Particle Astrophysics (CosPA2011), October 28-31, 2011, Beijing, Chin