2 papers
gr-qc2026
Second-Order Bi-Scalar-Vector-Tensor Field Equations Compatible with Conservation of Charge in a Space of Four-Dimensions
Gregory W. Horndeski
The purpose of this paper is to explore, in a space of four-dimensions, the possible forms that second-order, bi-scalar-vector-tensor field equations derivable from a variational p…
gr-qc2025
Second-Order Bi-Scalar-Tensor Field Equations in a Space of Four-Dimensions
Gregory W. Horndeski
Lagrange scalar densities which are concomitants of two scalar fields, a pseudo-Riemannian metric tensor, and their derivatives of arbitrary differential order are investigated in…