Global Dynamics in Infinitely Repeated Games with Additively Separable Continuous Payoffs

This paper studies a class of infinitely repeated games with two players in which the action space of each player is an interval, and the one-shot payoff of each player is additively separable in their actions. We define an immediately reactive equilibrium (IRE) as a pure-strategy subgame perfect equilibrium such that each player's action in each period is a stationary function of the other player's last action. We completely characterize IREs and their dynamics in terms of certain indifference curves. In a special case we establish a folk-type theorem using only IREs that are continuous and punish deviations in a minimal way. Our results are used to show that in a prisoners' dilemma game with observable mixed strategies, gradual cooperation occurs when the players are sufficiently patient, and that in a certain duopoly game, kinked demand curves emerge naturally.Immediately reactive equilibria, Additively separable pay-offs, Kinked demand, Gradual cooperation, Prisoners'dilemma

Immediately Reactive Equilibria in Infinitely Repeated Games with Additively Separable Continuous Payoffs

This paper studies a class of infinitely repeated games with two players in which the action space of each player is an interval, and the one-shot payoff of each player is additively separable in their actions. We define an immediately reactive equilibrium (IRE) as a pure-strategy subgame perfect equilibrium such that the action of each player is a stationary function of the last action of the other player. We show that the set of IREs in the simultaneous move game is identical to that in the alternating move game. In both games, IREs are completely characterized in terms of indifference curves associated with what we call effective payoffs. A folk-type theorem using only IREs is established in a special case. Our results are applied to a prisoner's dilemma game with observable mixed strategies and a duopoly game. In the latter game, kinked demand curves with a globally stable steady state are derived.

Global Dynamics in Repeated Games with Additively Separable Payoffs

This paper studies the global dynamics of a class of infinitely repeated two-player games in which the action space of each player is an interval, and the one-shot payoff of each player is additively separable in their actions. We define an immediately reactive equilibrium (IRE) as a pure-strategy subgame perfect equilibrium such that each player's action is a stationary function of the opponent's last action. We completely characterize IREs and their dynamics in terms of certain indifference curves. Our results are used to show that in a prisoners' dilemma game with observable mixed strategies, gradual cooperation occurs when the players are sufficiently patient, and that in a certain duopoly game, kinked demand curves emerge naturally.Immediately reactive equilibria, Additively separable payoffs, Kinked demand, Gradual cooperation, Prisoners' dilemma

Threats or Promises?: A Simple Explanation of Gradual Trade Liberalization

We analyze a infinitely repeated tariff-setting game by two large countries with alternating moves. We focus on the subgame perfect equilibria in which each country chooses its tariff according to a stationary function of the other country's tariff. We show that there are many equilibria with two steady states, one with higher tariffs (but still lower than the static Nash tariffs), the other with lower tariffs. We also show that there is a special class of equilibria in which there exists a unique, globally stable steady state. In both types of equilibria, one country unilaterally reduces its tariff from the static Nash equilibrium, the other country reciprocates in response to the first country's implicit "promise" to lower its tariff even further, and this process continues forever, converging to a steady state with tariffs lower than the static Nash tariffs. Therefore it is promises, rather than threats, that induce the countries to gradually reduce their tariffs.

Threats or Promises? A Built-in Mechanism of Gradual Reciprocal Trade Liberalization

We analyze an infinitely repeated tariff-setting game played by two large countries with alternating moves. We focus on the subgame perfect equilibria in which each country chooses its tariff according to a stationary function of the other country's tariff. We show that there are many equilibria with two steady states, one with higher tariffs (but still lower than the static Nash tariffs), the other with lower tariffs. We also show that there is a special class of equilibria in which there exists a unique, globally stable steady state. In both types of equilibria, one country unilaterally reduces its tariff from the static Nash equilibrium, the other country reciprocates in response to the first country's implicit "promise" to lower its tariff even further, and this process continues forever, converging to a steady state with tariffs lower than the static Nash tariffs. Therefore, promises, rather than threats, induce countries to gradually reduce their tariffs.

The First Systematic Survey for Lyman Alpha Emitters at z=7.3 with Red-sensitive Subaru/Suprime-Cam

We have performed deep imaging surveys for LyA emitters (LAEs) at redshift ~7.3 in two blank fields, the Subaru Deep Field (SDF) and the Subaru/XMM-Newton Deep survey Field (SXDF), using the Subaru/Suprime-Cam equipped with new red-sensitive CCDs and a new narrow-band filter, NB1006 (lambda_c=10052 Ang, FWHM=214 Ang). We identified four objects as LAE candidates that exhibit luminosity excess in NB1006. By carrying out deep follow-up spectroscopy for three of them using Subaru/FOCAS and Keck/DEIMOS, a definitively asymmetric emission line is detected for one of them, SXDF-NB1006-2. Assuming this line is LyA, this object is a LAE at z=7.215 which has luminosity of 1.2^{+1.5}_{-0.6} x 10^43 [erg s-1] and a weighted skewness S_w=4.90+-0.86. Another object, SDF-NB1006-2, shows variable photometry and is thus probably a quasar (QSO) or an active galactic nucleus (AGN). It shows an asymmetric emission line at 10076 Ang, which may be due to either LyA at z=7.288 or [OII] at z=1.703. The third object, SDF-NB1006-1, is likely a galaxy with temporal luminosity enhancement associated with a supernova explosion, as the brightness of this object varies between the observed epochs. Its spectrum does not show any emission lines. The inferred decrease in the number density of LAEs toward higher redshift is n_LyA(z=7.3)/n_LyA(z=5.7) = 0.05^+0.11_-0.05 from z=5.7 to 7.3 down to L(LyA)=1.0 x 10^43 [erg s-1]. The present result is consistent with the interpretation in previous studies that the neutral hydrogen fraction is rapidly increasing from z=5.7 to 7.3.Comment: 12 pages, 11 figures, Accepted to Ap

Neutrino emissions in all flavors up to the pre-bounce of massive stars and the possibility of their detections

This paper is a sequel to our previous one (Kato et al.2015), which calculated the luminosities and spectra of electron-type anti-neutrinos ($\bar{\nu}_e$'s) from the progenitors of core-collapse supernovae. Expecting that a capability to detect electron-type neutrinos ($\nu_e$'s) will increase dramatically with the emergence of liquid-argon detectors such as DUNE, we broaden the scope in this study to include all-flavors of neutrinos emitted from the pre-bounce phase. We pick up three progenitor models of an electron capture supernova (ECSN) and iron-core collapse supernovae (FeCCSNe). We find that the number luminosities reach $\sim10^{57} \mathrm{s^{-1}}$ and $\sim10^{53} \mathrm{s^{-1}}$ at maximum for $\nu_e$ and $\bar{\nu}_e$, respectively. We also estimate the numbers of detection events at terrestrial neutrino detectors including DUNE, taking flavor oscillations into account and assuming the distance to the progenitors to be 200 pc. It is demonstrated that $\bar{\nu}_e$'s from the ECSN-progenitor will be undetected at almost all detectors, whereas we will be able to observe $\gtrsim$15900 $\nu_e$'s at DUNE for the inverted mass hierarchy. From the FeCCSN-progenitors, the number of $\bar{\nu}_e$ events will be largest for JUNO, 200-900 $\bar{\nu}_e$'s, depending on the mass hierarchy whereas the number of $\nu_e$ events at DUNE is $\gtrsim$2100 for the inverted mass hierarchy. These results imply that the detection of $\bar{\nu}_e$'s is useful to distinguish FeCCSN- from ECSN-progenitors, while $\nu_e$'s will provide us with detailed information on the collapse phase regardless of the type and mass of progenitor.Comment: 22 pages, 14 figures, 4 tables, accepted to Ap

HMGN5 (High Mobility Group Nucleosome binding domain 5)

HMGN5 is a member of the high mobility group nucleosome binding domain (HMGN) protein family. HMGN proteins are ubiquitously expressed in vertebrate cells. They are nuclear proteins that bind specifically to nucleosomes without specificity for the DNA sequence and affect the structure and function of chromatin. HMGN5 sequences have been detected in all vertebrate tissues examines. HMGN5 differs from the other members of the HMGN family in that it is significantly larger and its amino acid sequence varies significantly between different vertebrate species