13 papers
Differential Obstructions to Curvature-Dependent Conformal Transformations
David S. Pereira, Francisco S. N. Lobo, José Pedro Mimoso
Curvature-dependent conformal rules are local forward assignments on known metrics, but they are not generically local changes of metric variables. We study the nondegenerate class…
Vacuum Gravity from Entropy: Stability, Spectra, and Exact Waves
David S. Pereira
We analyze the vacuum dynamics of Gravity from Entropy, including its algebraically constrained -field formulation. Evaluating the curvature traces over zero-, one-, and two-for…
Gravitational Waves as Thermodynamic Shear Excitations in Scalar-Tensor Gravity
David S. Pereira
Can a propagating spin--2 mode participate in a local thermodynamic process without assigning an autonomous entropy or a unique local energy to the wave itself? We show that this o…
First-order thermodynamics of multi-scalar-tensor gravity
David S. Pereira
We formulate a first-order thermodynamic description of Jordan-frame tensor--multi-scalar gravity. We derive the exact covariant split of the geometric sector and recast it a…
Big Bang Nucleosynthesis constraints on gravity
Daniel F. P. Cruz, David S. Pereira, Francisco S. N. Lobo +1
We investigate Big Bang Nucleosynthesis (BBN) in the framework of gravity, where the gravitational Lagrangian depends on the torsion scalar and the matter Lagrangian…
Gravitational baryogenesis beyond the spectator approximation
David S. Pereira, Beatriz A. Fernandes, José Pedro Mimoso
The standard gravitational-baryogenesis operator , with , is usually treated as a spectator interaction that generates an effective ch…