A New Method for Increasing COP of Heat Pump Cycle

Article信州大学工学部紀要 35: 11-18 (1973)departmental bulletin pape

The most general second-order field equations of bi-scalar-tensor theory in four dimensions

The Horndeski theory is known as the most general scalar-tensor theory with second-order field equations. In this paper, we explore the bi-scalar extension of the Horndeski theory. Following Horndeski's approach, we determine all the possible terms appearing in the second-order field equations of the bi-scalar-tensor theory. We compare the field equations with those of the generalized multi-Galileons, and confirm that our theory contains new terms that are not included in the latter theory. We also discuss the construction of the Lagrangian leading to our most general field equations.Comment: 21 page

Full bispectra from primordial scalar and tensor perturbations in the most general single-field inflation model

We compute the full bispectra, namely both auto- and cross- bispectra, of primordial curvature and tensor perturbations in the most general single-field inflation model whose scalar and gravitational equations of motion are of second order. The formulae in the limits of k-inflation and potential-driven inflation are also given. These expressions are useful for estimating the full bispectra of temperature and polarization anisotropies of the cosmic microwave background radiation.Comment: 20 pages, 5 figures, accepted to PTE