Further Monetary Easing Policies under the Non-negativity Constraints of Nominal Interest Rates: Summary of the Discussion Based on Japan's Experience

This paper examines issues surrounding monetary policy under zero interest rates based on one and a half yearfs experience in Japan. After reviewing the market development in Japan, it summarizes the transmission mechanism of monetary policy under zero nominal interest rates, and considers what would be the likely policy options if a central bank were to conduct further monetary easing. Specifically, a more detailed policy announcement is regarded as feasible, less costly, and the less risky option, although additional effects of monetary easing through this measure are relatively limited. On the other hand, introduction of a temporary fixed exchange rate system and a huge increase in the outright purchase of medium- and long-term government bonds can induce relatively large effects, although the uncertainty in the effects as well as the accompanied costs and risks may be very large. In addition, the paper considers the validity of introducing inflation targeting. It summarizes that inflation targeting is not necessarily easy to distinguish from traditional policy management based on an overall consideration. Furthermore, given recent tendencies in Japan, the paper argues that the introduction of inflation targeting in the current situation might impair the conduct of monetary policy in the absence of preconditions for benefiting from its intrinsic merits.

Hillclimbing Higgs inflation

We propose a realization of cosmic inflation with the Higgs field when the Higgs potential has degenerate vacua by employing the recently proposed idea of hillclimbing inflation. The resultant inflationary predictions exhibit a sizable deviation from those of the ordinary Higgs inflation.Comment: 5 pages, 3 figures, 1 table (v1); published version, references and footnotes added (v2

Hillclimbing inflation in metric and Palatini formulations

A new setup of cosmic inflation with a periodic inflaton potential and conformal factor is discussed in the metric and Palatini formulations of gravity. As a concrete example, we focus on a natural-inflation-like inflaton potential, and show that the inflationary predictions fall into the allowed region of cosmic microwave background observations in both formulations.Comment: 8 pages, 9 figure

Constraints on extended Jordan-Brans-Dicke gravity

Cosmological analysis of extended Jordan-Brans-Dicke (eJBD) gravity is presented in the Einstein metric frame in which gravitational interaction is readily understandable. Our formulation is the first systematic investigation of how to introduce lagrangian of standard particle physics in eJBD framework consistently with the general principle of spontaneously broken gauge symmetry, which makes it possible to confront eJBD-based cosmology with observational and laboratory bounds on time variation of parameters, masses, and coupling constants, caused by time evolution of eJBD fields. Decomposition of standard particle physics lagrangian into independent gauge invariant pieces is proposed to avoid serious conflict that may arise from standard lagrangian transformed from the Jordan frame. Independent conformal factors are assigned to each of five gauge invariant pieces. The formulation is most unambiguously made possible by defining fields having canonical kinetic terms that allow us to use the canonical quantization rule of field theory. This construction gives as one of its consequences the canonical eJBD field $\chi$ that couples to the universal fermion current, a linear combination of baryon and lepton number currents, $\partial_{\mu} \chi (\frac{1}{3} j_B^{\mu} + j_L^{\mu})$, in addition to the conventional trace of the energy-momentum tensor. Field equation of eJBD field along with gravitational equation is analyzed by using a simplified polynomial class of potential and conformal functions, giving time evolution of radiation, matter and dark energy densities consistent with observations when an appropriate set of model parameters are used. Finite temperature corrections are further calculated to give temperature dependent terms in eJBD field potential.Comment: 25 pages and 4 figure

Gravitational and dark wave emission at binary merger

The recently proposed formalism of extended Jordan-Brans-Dicke gravity makes it possible to calculate energy loss rate due to both gravitational wave and scalar field (giving the origin of dark energy) wave emission at merger of a black hole and a neutron star; a binary system of no scalar hair and a star with the scalar charge. The scalar field emission changes orbit parameters of the binary system, thereby changes detectable gravitational wave emission. When neutron stars carry significantly large scalar charge, significant dark wave (namely, scalar field wave) emission occurs at the same time of gravitational wave emission. It is found that solutions of coupled differential equations predict non-vanishing remnant dark charge after the gravitational collapse. This gives two interesting possibilities: (1) the no-hair conjecture of black hole is violated, or (2) a bosonic cloud is formed outside the event horizon of black hole. The bosonic cloud proposed in the literature is a gigantic atom made of gravitationally bound dark energy quanta surrounding a black hole. One can either constrain, or even determine, parameters of extended Jordan-Brans-Dicke gravity from accumulated gravitational wave observations of merging black hole and neutron star.Comment: 9 pages, 2 figure

Neutral solution low in glucose degradation products is associated with less peritoneal fibrosis and vascular sclerosis in patients receiving peritoneal dialysis.

BACKGROUND: The effects of novel biocompatible peritoneal dialysis (PD) solutions on human peritoneal membrane pathology have yet to be determined. Quantitative evaluation of human peritoneal biopsy specimens may reveal the effects of the new solutions on peritoneal membrane pathology. METHODS: Peritoneal specimens from 24 PD patients being treated with either acidic solution containing high-glucose degradation products [GDPs (n = 12)]or neutral solution with low GDPs (n = 12) were investigated at the end of PD. As controls, pre-PD peritoneal specimens, obtained from 13 patients at PD catheter insertion, were also investigated. The extent of peritoneal fibrosis, vascular sclerosis, and advanced glycation end-product (AGE) accumulation were evaluated by quantitative or semi-quantitative methods. The average densities of CD31-positive vessels and podoplanin-positive lymphatic vessels were also determined. RESULTS: Peritoneal membrane fibrosis, vascular sclerosis, and AGE accumulation were significantly suppressed in the neutral group compared with the acidic group. The neutral group also showed lower peritoneal equilibration test scores and preserved ultrafiltration volume. The density of blood capillaries, but not of lymphatic capillaries, was significantly increased in the neutral group compared with the acidic and pre-PD groups. CONCLUSIONS: Neutral solutions with low GDPs are associated with less peritoneal membrane fibrosis and vascular sclerosis through suppression of AGE accumulation. However, contrary to expectation, blood capillary density was increased in the neutral group. The altered contents of the new PD solutions modified peritoneal membrane morphology and function in patients undergoing PD