Firm's reduction of greenhouse gas emissions and economic performance: analyzing effects through demand and productivity

This paper analyzes how a firmfs reduction of its greenhouse gas (GHG) emissions affects its economic performance. The theoretical model used is derived from the Cobb-Douglas production function and the inverse demand function, and predicts that in reducing its GHG emissions, a firm will increase its value added because it promotes an increase in demand for its output and improves its productivity. The estimation results, using data on Japanese manufacturing firms, suggest that the reduction of GHG emissions increases a firmfs economic performance only through an increase in demand. Thus, firms can improve their overall economic performance because increased demand accompanies their reduction of GHG emissions, even if they cannot achieve this through an improvement in productivity, as estimates here support the traditional view that reducing GHG emissions imposes additional costs on firms.Reduction of greenhouse gas emissions, Economic performance, Increase in demand, Improvement in productivity, Instrumental variables model

Early Spectroscopy of the 2010 Outburst of U Scorpii

We present early spectroscopy of the recurrent nova U~Sco during the outburst in 2010. We successfully obtained time-series spectra at $t_{\rm d}=$0.37--0.44~d, where $t_{\rm d}$ denotes the time from the discovery of the present outburst. This is the first time-resolved spectroscopy on the first night of U Sco outbursts. At $t_{\rm d}\sim 0.4$~d the H$\alpha$ line consists of a blue-shifted ($-5000$ km s$^{-1}$) narrow absorption component and a wide emission component having triple peaks, a blue ($\sim -3000$ km s$^{-1}$), a central ($\sim 0$ km s$^{-1}$) and a red ($\sim +3000$ km s$^{-1}$) ones. The blue and red peaks developed more rapidly than the central one during the first night. This rapid variation would be caused by the growth of aspherical wind produced during the earliest stage of the outburst. At $t_{\rm d}=1.4$~d the H$\alpha$ line has a nearly flat-topped profile with weak blue and red peaks at $\sim \pm 3000$ km s$^{-1}$. This profile can be attributed to a nearly spherical shell, while the asphericity growing on the first night still remains. The wind asphericity is less significant after $t_{\rm d}=9$ d.Comment: 5 pages, 3 figures, Accepted for publication of PASJ Letter

A 125 GeV Higgs Boson Mass and Gravitino Dark Matter in R-invariant Direct Gauge Mediation

We discuss the SM-like Higgs boson mass in the MSSM in an R-invariant direct gauge mediation model with the gravitino mass in the O(1) keV range. The gravitino dark matter scenario in this mass range is a good candidate for a slightly warm dark matter. We show that the Higgs boson mass around 125 GeV suggested by the ATLAS and CMS experiments can be easily achieved in the direct gauge mediation model with this gravitino mass range.Comment: 15 pages, 6 figures; v2: section 5 added (version accepted for the publication of PLB

Cosmic Ray Positron and Electron Excess from Hidden-Fermion Dark Matter Decays

The anomalies observed in recent cosmic ray experiments seem to strongly constrain the nature of the dark matter. In this letter, we investigate a possibility of the fermionic dark matter with a minimal extension of the standard model. We found that the dark matter decays caused by the dimension six operators can naturally explain the anomalies.Comment: 10 pages, 8 figures, accepted by PL

Reheating of the universe after inflation with f(phi)R gravity

We show that reheating of the universe occurs spontaneously in a broad class of inflation models with f(phi)R gravity (phi is inflaton). The model does not require explicit couplings between phi and bosonic or fermionic matter fields. The couplings arise spontaneously when phi settles in the vacuum expectation value (vev) and oscillates, with coupling constants given by derivatives of f(phi) at the vev and the mass of resulting bosonic or fermionic fields. This mechanism allows inflaton quanta to decay into any fields which are not conformally invariant in f(phi)R gravity theories.Comment: 4 pages, (v2) references added, (v3) revised to have inflaton quanta canonically normalize