Occurrence of Hyperon Superfluidity in Neutron Star Cores

Superfluidity of $\Lambda$ and $\Sigma^-$ admixed in neutron star (NS) cores is investigated realistically for hyperon ($Y$)-mixed NS models obtained using a $G$-matrix-based effective interaction approach. Numerical results for the equation of state (EOS) with the mixing ratios of the respective components and the hyperon energy gaps including the temperature dependence are presented. These are meant to serve as physical inputs for $Y$-cooling calculations of NSs. By paying attention to the uncertainties of the EOS and the $YY$ interactions, it is shown that both $\Lambda$ and $\Sigma^-$ are superfluid as soon as they appear although the magnitude of the critical temperature and the density region where superfluidity exists depend considerably on the $YY$ pairing potential. Considering momentum triangle condition and the occurrence of superfluidity, it is found that a so-called `` hyperon cooling\rq\rq~(neutrino-emission from direct Urca process including $Y$) combined with $Y$-superfluidity may be able to account for observations of the colder class of NSs. It is remarked that $\Lambda$-hyperons play a decisive role in the hyperon cooling scenario. Some comments are given regarding the consequences of the less attractive $\Lambda\Lambda$ interaction recently suggested by the `` NAGARA event\rq\rq~$^6_{\Lambda\Lambda}$He.Comment: 25 pages, 12figures; final version; will appear in Prog. THeor. Phys. Vol.115, No.

Double giant dipole resonances in time-dependent density-matrix theory

The strength functions of the DGDRs in 16O and 40Ca are calculated using an extended version of TDHF known as the time-dependent density-matrix theory (TDDM). The calculations are done in a self-consistent manner, in which the same Skyrme force as that used for the mean-field potential is used as the residual interaction to calculate two-body correlations. It is found that the DGDR in 16O has a large width due to the Landau damping, although the centroid energy of the DGDR is close to twice the energy of the GDR calculated in RPA. The DGDR in 40Ca is found more harmonic than that in 16O.Comment: 4 pages, 3 figure

Nondominated equilibrium solutions of multiobjective two-person nonzero-sum games in normal and extensive forms

In this paper, we review the development of studies on multiobjective noncooperative games, and particularly we focus on nondominated equilibrium solutions in multiobjective two-person nonzero-sum games in normal and extensive forms. After outlining studies related to multiobjective noncooperative games, we treat multiobjective two-person nonzero-sum games in normal form, and a mathematical programming problem yielding nondominated equilibrium solutions is shown. As for extensive form games, we first provide a game representation of the sequence form, and then formulate a mathematical programming problem for obtaining nondominated equilibrium solutions

From Manchuria to post-war Japan: knowledge transfer through in-house training at the South Manchuria Railway Company (SMR)

One important question in history is how knowledge has spread and allowed participants in an economy to increase their human capital. As Easterly and Levine have suggested (2001), one possible source of Japan’s post-war growth was the increased size of the labour force and improved human capital. Their data show that Japan’s experience was different from that of post-war Europe, where sources of growth mainly came from the high levels of investment, rather than from human resources. My research goes back to imperial Japan to analyse one possible channel of human capital development – the in-house vocational training offered by the largest Japanese wartime public corporation, the South Manchuria Railway Company (SMR). The majority of the 140,000 Japanese staff members were higher-elementary school graduates. They worked as staff members engaged in railway operation and construction, station duties, or worked as factory workers, and received extensive on-the-job training. A limited number of capable young employees were invited to attend training schools within the company. These programs were also open to non-Japanese staff members, but most participants were Japanese. Corporate training became increasingly common after the Second Sino-Japanese War broke out in 1937 to fill the vacancies created as a result of the intensified conscription. Although some people died in the war, many returned to Japan and entered the post-war labour market armed with their wartime skills and knowledge. The paper argues that training opportunities provided to under-educated young Japanese individuals at the SMR and other public corporations in the overseas empire produced unanticipated benefits in the form of human capital development

An Alternative Characterization of Efficient Group Strategy-Proof Rules in Linear Production Economies with Convex Preferences

In linear production economies, Maniquet and Sprumont（1999）characterized Pareto-efficient and group strategy-proof rules. This paper shows an alternative characterization of the rules by Pareto-efficiency, strategy-proofness, and strong non-bossiness（Ritz, 1983）when the preferences are continuous, strictly monotonic, and convex.departmental bulletin pape